Hey, Psych2Goers. Do you know what emotional detachment is? It refers to one's inability to connect with another emotionally or the avoidance of doing so. People who are emotionally detached may find themselves closed off to others or will actively avoid them or any situation that will evoke an emotional response. It may happen by choice or as a result of trauma. In general, emotional detachment is a protective measure to prevent you from getting harmed by others. To learn more about this, here are seven signs you're emotionally detached. Number one, you feel numb all the time. Is it difficult for you to identify or to feel any of your own emotions? Maybe you struggle to have an emotional response to other people and situations. Well, the biggest sign of emotional detachment is feeling detached from people and situations. You may struggle to feel anything at all or you're actively trying to avoid feeling anything. However, this numbness can end up making it difficult to enjoy activities or relationships, which can put a huge strain on the quality of your life. Number two, you avoid other people's emotions. Do you find yourself disconnected from other people? Perhaps it's hard to listen to other people talk about their emotions and respond to them. Or maybe you just don't have the energy to put up with other people's emotions and so you avoid them. Since emotional detachment makes it difficult to connect with others, you may find yourself growing distant between yourself and those close to you as a result your relationships may suffer and sometimes fade out. Number three, you are non-committal. Are you bad at keeping up with others? Because emotional detachment can make it difficult to form attachments, it can make it very hard to commit to situations or people. Existing relationships may end and new relationships are unlikely to form. People who are emotionally detached often also have difficulties making what should be a priority a priority. Therefore the needs of others may fall by the wayside. Number four, you isolate yourself. Do you always keep to yourself and feel like you don't really need to go out? Self isolating can be used as a tool to keep negative emotions from forming. This self isolation can further strain relationships and at worst create and worsen other mental health problems. While it is natural to want to take some time for yourself once in a while, it can be harmful if the habit becomes excessive and sudden. Number five, you find it hard to express yourself to others. If you are emotionally detached, it can be insanely difficult to feel strong emotions towards anything. Because of this, you may often have a hard time identifying what you are feeling, let alone expressing that and sharing it with someone else. As a result, you may come across as reserved, aloof and cold to others. Number six, you have another mental health condition. Emotional detachment is often part of another disorder. Most commonly it's found in people with depression, PTSD, bipolar, personality disorders, and in some cases people on the autism spectrum. It can also be caused by medication that is taken to treat any disorder, as it is a defense mechanism. It has a higher prevalence among disorders involving any kind of trauma. And number seven, you avoid situations. People who are emotionally detached and especially those who are trauma survivors may avoid situations that remind them of past events. Typically in these scenarios, they will actively avoid situations where they know they'd feel a strong emotion if they were there. However, in actively avoiding certain environments, events or situations, they may be more prone to isolate themselves. Did you relate to any of these points? Let us know in the comments below. If you found this video helpful, be sure to like, subscribe, and share this video with those who might benefit from it. And don't forget to hit the notification bell icon to get notified whenever Psych2Go posts a new video. As always, the references and studies used in this video are added in the description below. Thanks for watching and see you in the next video.


The concrete design for our highways, bridges, and other structures is intended to be of the highest quality. It should consist of approved materials that are correctly proportioned and mixed, and then carefully transported to the job and placed. In practice, however, the concrete ordered for the job may not be the concrete that's actually placed. At critical points during production, transport, or handling on site, the concrete's quality may be jeopardized. Bature mixer slips are not always a guarantee that you have the right concrete in the truck. For example, if wash water was left in the truck before it was loaded, the mix may be too wet, or the truck driver may decide to add water if the mix begins to stiffen. So it's important, and it's required, that the quality of the concrete be verified before the concrete is cast. Verification is provided by conventional control tests performed in the field. This presentation is the first of four videotapes on quality control of concrete on site. Here in part one, and in part two, are presented the conventional control tests for determining concrete quality at the job site. In parts three and four, you'll see new quality control procedures that have been developed by Sharp and others for testing concrete both before and after it's cast. So, here in part one, we'll look at sampling concrete, and at the test methods for temperature and slump. In part two, we'll look at the test methods for air content and unit weight, as well as the procedures for making cylinders and beams. Our first topic, then, is sampling. Before any of the tests can be performed, a sample of the concrete is needed, a representative sample. The concrete to be tested has to be typical of the entire truck load. Sampling should be done according to Ashtow designation T141. The basic rule is this. Don't take the sample from the beginning or end of the discharge. Take it from the first one-third of the discharge, but never from the first two cubic feet. To obtain the sample, either the entire stream should be caught in a container, or the chute should be swung over to the side. The important point is to get the entire stream. Cutting the stream in half, like this, is unacceptable. The rim of the bucket will knock some of the large aggregate out of the sample. The sample should be mixed with a shovel just until it has a uniform appearance. Then it should be covered to protect it from the sun and the wind. Samples must not be allowed to dry out. One last point. Testing must be completed within 15 minutes after obtaining the sample. Now, temperature. The temperature of fresh concrete affects the rate at which concrete gains strength, the amount of strength the concrete ultimately acquires, and the porosity of the concrete. Checking concrete temperature is simple. It should be done according to ASTMC 1064. All that's needed is a standard thermometer, such as an ASTM liquid in glass type, or a metal immersion type. The thermometer is inserted into the fresh sample so that the temperature-sensing portion is submerged at least three inches. The concrete should be gently pressed around the thermometer so that the air temperature does not affect the reading. The thermometer is left in the concrete for two minutes or until the temperature stabilizes. Then the temperature is recorded. The measurement must be completed within five minutes after the sample is obtained. The temperature of in-place concrete is measured in the same way. Now, the air temperatures during concrete construction are also important. The high and low air temperatures must be monitored daily. Next on the list is the slump test, AASHTO T119. This is by far the oldest and most widely used test to measure the uniformity and consistency of concrete. Variations in slump generally indicate that changes have occurred in the properties or proportions of cement, aggregates, water, or admixtures. The equipment needed for slump tests includes a standard slump cone, a standard tamping rod, a scoop, a base, and a ruler or measuring tape. The slump cone should be reasonably clean, especially inside. The surfaces should be smooth with no dried concrete on them. Also, there should be no major dents. A standard tamping rod is smooth with a rounded tip. Makeshift rods, such as cut-off reinforcing bar, are unacceptable. The base for the cone must be strong, rigid, and stable enough to support the tester as well as the concrete and equipment. It needs to be level and firmly supported so that it won't rock or bounce. The sample should be brought close to the test location and remixed if necessary until it looks uniform. The test is begun by first dampening the inside of the slump cone to keep the concrete from sticking to it. Then, the base is dampened as well, so that it won't absorb water from the concrete. But no freestanding water should be left on the base. The cone should be set down on the base as close as possible to the sample. Next, the technician steps onto the footholds at the bottom of the cone and stays there. That's why the sample and cone need to be close to each other. The cone is filled by moving the scoop around the top to distribute the concrete as evenly as possible. The filling is done in three layers. Each layer should take up approximately one-third of the cone's volume. So the first layer should come up about two and a half inches from the base. The second layer should come up about six inches. That's about halfway up the cone. And the third layer should overflow the cone. As each layer is placed in the cone, it's consolidated with a tamping rod. Starting at the perimeter, with its rounded tip downward, the rod is inclined slightly to match the slope of the cone. Otherwise, the concrete closest to the cone's sides will not be properly consolidated. The rodding should go to the bottom of this first layer, but just tap the base. Each layer is rotted 25 times, with about half of the strokes made near the perimeter. A spiraling pattern should be followed as the rod moves toward the center of the cone. The strokes are distributed uniformly. As the rod is moved away from the perimeter, it's returned to the vertical. The second layer fills about half of the cone's height. It's rotted the same as the first with one difference. The rodding should just penetrate about a half inch into the first layer, not all the way down to the base. The third layer should overflow the cone. That way, the concrete stays above the cone throughout the rodding. If it drops below the top, the rodding should be stopped. More concrete should be added, and then the 25 spiraling strokes should be completed. And the rod should just penetrate the top of the second layer, about one half inch. With the cone full and the rodding completed, the surface of the concrete is struck off by moving the tamping rod across it in a screening and rolling motion. The concrete surface must be level and fairly smooth. Next, any concrete that is spilled around the bottom of the cone must be removed. Otherwise, it may keep the sample from slumping properly when the cone is lifted off. However, the technician must be careful not to move the cone and disturb the concrete. Basically, both sides of the cone must be held still by pressure on either the handholds or footholds until the cone is removed. To remove the cone, both hands are placed on the handholds and downward pressure is applied to keep the cone stable before the feet are removed from the footholds. Now the cone is pulled straight up, slowly and steadily, without twisting or tilting. The removal should be completed in about five seconds. Slowly enough that the concrete doesn't pull on the cone. The cone is then set on the base next to the concrete without touching the concrete or jarring the base. Immediately, the tamping rod is laid flat across the top of the cone extending over the concrete. A ruler or measuring tape is used to measure the distance between the bottom of the rod and the top of the concrete. The measurement should be made to a point that is directly above the center of the bottom of the concrete, not at the center of the top. The entire slump test must be accomplished within two minutes as measured between the adding of the first layer and the measuring of the slump. And that's sampling temperature and slump and the end of part one. In part two, we'll cover air content, unit weight and the making of cylinders and beams.


Welcome. Today we're going to be talking about ten habits that millionaires have, almost every single millionaire. So I've done studying of millionaires, of billionaires, of extremely successful people. And one thing that you'll start to notice when you study successful people is that there seems to be a pattern that a lot of them have. And so what I've done is I've taken the ten most prevalent habits, the ones that I see the most, the most common ones of millionaires, and I want to teach them to you because regardless of your craft, regardless of what you do or your profession, these ten habits will not only help you in your business, they not will only help you make more money, they will just help you in life as well. So the first habit that I noticed with a lot of millionaires is that they set their mind to mastering their craft. Whatever it is, they set their mind to mastering their craft. And it's interesting because I was watching something the other day where it was The Rock and he was talking to Jason Strahan, they were at the Oscars, and it was interesting because I looked at both of them and realized for both of them, they have mastered one thing and they moved on to the next thing and mastered that as well. And so with The Rock, you know, he started off, he went to college at the University of Miami, he played football for them, after that he became a professional wrestler for TV, and then after that he became an actor and he's the highest paid actor out of last year. Then you have Jason Strahan, who is another guy who didn't play football until he was a junior in high school, then got a scholarship to go to college, went into the NFL, and then went into the NFL and won a Super Bowl, and then after that went on to Good Morning America and he's mastered a couple different things. And one thing that they all do is they set their mind on mastering their craft. They put a lot of really hard work into whatever it is. They crave mastery, the 10,000 hour rule. They do as much as they possibly can to get as good as they possibly can and as short of amount of period as they possibly can as well. So that's the first thing that you have to realize is they master their craft. The next thing that I've actually noticed with a lot of successful people is that they exercise. I personally believe that the gym and exercising is very much equivalent to life and success. Because there's always reasons why you can't go to the gym. There's always excuses you can give yourself on why you should eat that pasta or that pizza, but there's also other reasons, and that's the gym. If you think about life as well, there's always reasons why you shouldn't wake up early. There's always reasons why you shouldn't make cold calls or do what you're supposed to do. And so they exercise. The reason why is because it gives you a healthy mentality, number one. It gives you a healthy body, and the more in shape that you are, the more energy you have, the more energy they have to go every single day, and it releases stress to go to the gym as well. So the second thing is that they like to exercise. The third thing, which is a huge thing, is that they read every single day. That's an interesting thing. Is that the people who are the most successful are constantly trying to make themselves better. Which is crazy because you have people in this world that aren't to where they want to be. They're not in the place that they want to be, and they don't read. They don't improve themselves. They don't work on personal growth or self-development. Warren Buffett is said to read eight hours a day. The third richest man in the world reads eight hours a day in order to improve himself. How much are you reading throughout the day? So read every day. The next thing that has to do with that is that they never stop learning. They can constantly make themselves a sponge. One of the reasons why people who are successful are constantly learning is because they know that they can always get better. They don't have a fixed mindset. They have a growth mindset. They're challenging themselves to get better. They're challenging themselves to get better in whatever it is that they do, whatever field that they're in. And then when you see people that are switching fields, like I was saying, like Jason Strahan or like The Rock, those two guys, they never stop learning. They're constantly reaching out to people. They constantly have mentors, whether they're paid mentors or whether they're mentors who are friends of theirs that are helping them improve and they're constantly learning and getting better. The next thing that I've found with successful people and with millionaires is that they are very good planners. Most people don't like to plan. I personally don't like to plan, but I force myself to do it because I know that it needs to be done. Whether it's, you know, planning your entire week on a Sunday or super simple thing, which if you want to start planning, this is the easiest way to do it.  Plan out the most important things that have to be done that day. And if you get nothing else done, as long as you get those most important things done, you will have a successful day. The next thing that I've noticed is that they set goals for themselves and their goals are very specific, right? They don't say, I want to make a million dollars or they don't say, I want to make more money this year. They say, I want to make a million dollars this year or a million dollars this month or whatever it is. They set very specific goals for themselves and they write it down. Most people don't know their exact goals are not extremely clear on what they want for their goals and then they don't even write it down. So they set goals for themselves and they work daily, weekly, monthly towards those goals. Another huge thing is that they wake up early. Jack Dorsey, who's the guy who started Twitter, he's known to wake up at five or six a.m. If you go through and look at the people who are the most successful in the world and you look at their habits of what time they wake up, I could give you a laundry list of people who wake up every single morning early, four o'clock, five o'clock, six o'clock, right? The reason why is because they're up when nobody else is up, when it's quiet and they could be the most productive in that time. The next thing is that they also keep a journal. They take all of their thoughts, everything that's running through their brain and they put it down on a piece of paper. The reason why that's extremely important, I didn't use to journal, but I force myself to journal every single day now and it's not like a diary, but I take everything that's running through my brain and put it on a piece of paper and try to use that to help myself plan for the week, for the day, for the month and for the year. They keep a journal of exactly what's going on in their life, what they need to improve at, how they're working to improve themselves, and that's how they're pushing themselves to become better as well. So they keep a journal. The next one is that they actually schedule free time. This was huge for me because I personally used to think that if I wasn't where I wanted to be in life, if I wasn't where I wanted to be in life, well, then I don't deserve to have a weekend offer. I don't deserve to have a night off. And it was up until I read a book called The One Thing where they said you have to schedule your free time. You have to schedule free time in. And the reason why is because if you have free time, you will be more productive when you go in and actually start working. Otherwise, you'll burn yourself out. I used to work 110 hours a week. I will never go back to that ever again. I promise you that. But they schedule their free time. They schedule their vacations so that they can relax, they can recharge, and then when they go back into working, they can work really hard at it and get everything done. So they're actually more productive by taking time off. And the last one, the interesting thing is that they are frugal. Most people think that in millionaires, they go out and they buy the most expensive things. But there's a great book called The Millionaire Next Door. And in that book, they talk about how the average millionaire is actually just your next door neighbor. There's someone who makes OK money, but they were smart with their money. They learned how to save. They learned that they don't need to buy new things all the time. They don't need to go out and buy a $100,000 car even if they've got that money saved. And they've realized that frugality is what they really work towards.  And they save money. And guess what? That's why they retire at 40 years old, is because the fact that they've worked really hard, they saved really hard up until 40. And instead of working until 65, 70 years old, they can eventually retire if they want to at 40 because they have enough money saved. They've been planning. Now, that being said, most of them don't retire. And the reason why is because they love what they do. They love pushing themselves, but they have the opportunity to. And so that's what you have to realize. Those are the 10 most common habits that I've found from successful millionaires. If you happen to know of any, reach out to me. Let me know if there's anything that you feel that I missed. But I hope that with this, you click the Subscribe button. And if you are interested in learning more about millionaires, I run a webinar called the Mindset of a Millionaire where I teach not only the steps in what they do, but I also teach what goes on in their mind as well. And you can access that by going to mwfmotivation.com slash webinar where it is free. But with that, I hope you have an amazing day.


Chechens help Palestine with this weapon, Kadirov. The tragic and heartbreaking events in the Gaza Strip do not leave anyone indifferent. The head of Chechnya Ramzan Kadirov said this, according to him the footage that the world sees every day demonstrates that every person is a witness to the genocide of the Palestinian Muslims. He noted that those who are responsible for these terrible crimes have long crossed unimaginable borders and turned almost the whole world against them, except for the same criminals and hypocrites who are in power in several Western countries. As we have seen, they are the ones who support Satanists and Nazis in Ukraine. Therefore, we are happy to fight with them within the framework of the Northern Military District. During all these days, residents of the Chechen Republic perform collective tahajud prayers in mosques in the region. They pray to Almighty God, wish mercy to the oppressed Palestinian people and victory to our brothers participating in a special military operation in Ukraine. After all, as you know, prayer is the most powerful weapon of Muslims.


The Siena Music Academy library in Siena is specialised in music and musicology. It is functional to the students attending our masterclasses, but also to researchers, scholars and music teachers of all levels. Using Alma means to share information about music scores and parts that would be otherwise kept in our palace and offer them to a broad range of users. Alma provides an easy way of contributing to the Italian National Library Service collective catalogue. This has opened our library to a wider national dimension ready to reach a larger number of musicians and musicologists. Besides, Alma is periodically implemented with new functions and templates, which allow the cataloger to treat an increasing number of items In a musical founder, we may have printed music, modern or ancient books, periodicals and even objects. Alma gives the possibility to list a variety of materials that had to be treated separately before using different softwares. Move to Alma was a good opportunity to consolidate the collaboration between the three university, Florence, Pisa and Siena, collaboration born in the past with SFX and Metalip and more recently with the adoption of Primo and bring it to a higher and more complex level with the definition of the network zone and the adoption of common cataloging moves. Thanks to Alma and its network zone, we contributed to the National Project SBN National Library Service maintaining a wide level of autonomy guaranteed by the flexibility of the new SBN architecture and the possibility to operate in its own working environment taking into account the local choices and the needs of different realities that contributed to SBN. The new architecture has allowed to share the cataloging at the network level with the creation of a single new SBN university traditional app, which has incorporated the historical work done by the Florentine Bar in the context of the National Cooperation and sanctioned the entry of the bar of Pisa and Siena in SBN. The adoption of this organizational model has led to the shift at the network level of many activities carried out so far at the local level. With the network zone, we have the ability to manage and maintain the authority file of orders and subject in addition to the verbal translation of the notifications. This simplified the procedures and the times of cataloging in an important element in a period of strong construction of the resources. Contributing to the National Catalogue is a great opportunity to give greater visibility to the collection of the libraries of the University of Siena and all the libraries that are part of the Sienese Library Service. Hi, I'm Francesco. I must challenge dramatically my work as a librarian. I must have a powerful tool and a possibility to work in a flexible way are incredible.


Cool. All right. Hello, everyone. Welcome to Thursday. What is this April 2nd? We're going to be, I'm sure, maybe like you, the days kind of all blur together a little bit now, although maybe it's different when you have to attend classes all the time online. So just some updates before we kind of get going. Midterm grades. So we'll release the midterm grades later today on Canvas. So what'll happen is we'll post it on there, so you'll be able to see through Canvas what your grade is. And then from there, if you want to see how you did, you can attend office hours and the TAs, and with the TAs or I, and we'll be happy to share your exam with you and go through it, which is what we normally do. Yes. At assignment four grades, we'll be releasing those tomorrow.  And I'll also be, I'll try to have some statistics ready for Tuesday. So yeah, I won't tell you who did it, but maybe I'll ask the, if there's one person that was particularly better than everyone else, I can ask them how they did it, and they can maybe tell us about it at the start of Tuesday's lecture, which I think would be pretty cool. No, it's about learning. There's no witch hunts. It's all about learning how we can better, how do you know that wasn't me in discord? Cool. And okay, for those that haven't started, I think, you know, I think we had a good there's, I could have been all of them. You don't know that. Those are simple accounts. Okay, so start on assignment five crack, start cracking those hashes. A lot of people have already finished. But still, you know, it's going to be possible to run into issues or maybe technical problems while doing this assignment. So please get started on that as soon as possible, so that we can help. So reach out for help in the on the piazza reach out for help on office hours. There's lots of that. You probably should write code for the custom hash. You can do it however you want to do it. All right, so let's go back to networking. So we talked actually, I can just take us back real quick. So we talked a lot about different types of attacks that we can have on a TCP connection. So somebody remind us, what was the so an attacker who wants to either spoof or hijack a TCP section, what's the key piece of information from that communication that an attacker needs to know in order to in order to be able to either successfully spoof or successfully hijack the connection. Yeah, so sequence of acknowledgement numbers and specifically the Vic the target that they're trying to talk to that specific sequence number, right? So either if it's a, if it's a hijack between a communication that's already ongoing, we need to know the sequence and acknowledgement numbers there. If we're trying to spoof and initiate a connection, we need the sequence number that the other side generates that we'll never see that packet. So this really, this is why we talked about if we go all the way back, why when we talked about as part of the TCP three way handshake, we create new sequence, a random sequence and acknowledgement numbers, specifically because of this, because if somebody can easily guess your sequence or acknowledgement number, then they can do all these attacks with spoofing and hijacking. Cool. Okay. So yeah, we talked about hijacking and we talked about that it causes this act storm where they start get desynced and start acting back and forth, which causes actually pretty cool attacks. Now we'll look at today a different type of attack. So we're going to, we are going to look at now a different type of attack. So, so when we think of spoofing and hijacking, what of the three aspects of security? So what were the three, the CIA triad, what were the three aspects there? So spoofing. So which was does spoofing match up with? Yeah, integrity, possibly confidentiality. If they're using, if they're using that identity in order to give secret information out. What about hijacking? Yeah, coming into integrity and right also availability, because we can, if we're able to hijack their communication, we can also disrupt it and stop their communication from happening. Cool. So okay, so we have this, now we're going to look at kind of another entire class of attacks on networks. And this is really kind of a key availability attack is essentially denial of service. So the idea is there's some victim out there on the internet. And we want to somehow basically have it be in many different ways where no one else can talk to that server. So that system is now completely off the internet. Nobody can talk to it. Let's talk about first, why would somebody want to maybe take down and deny service to a specific application from everybody else? Yeah, so maybe spite, that's a pretty good one. Maybe we just want to take them down a business competitor. So if they're a business competitor, we may want to take them down. Yeah, funny that you talked about Minecraft. This is a similar thing in like the days of IRC servers and some some things of that bragging rights. Yeah, providing cover, these are all good. One thing that happens a lot is basically, they'll do essentially, what's the word I'm looking for? So what they'll do is they'll take down a server so they'll target like a smaller medium size company as the victim, take it down and say, Hey, I offer anti denial of service protection. It looks like your website's down. If you hire me, I'll make sure that goes away.  Yeah, extortion. There we go. That's the word I was looking for. Wow. Right. So these are all and if you think about a if you're able to cause a denial of service attack on something like on something like Amazon, Amazon makes tons of money per second. So every even second or minute that they're down is time where they're losing money and it's significantly impacting their business. And so we're going to look at different types of denial of service attacks on the network and kind of see how that works. So yeah. Okay, so the first attack we're going to look at is just so the first thing we'll basically look at is sin flooding. So this actually has to do with how the three way handshake works and the really important thing to understand and really the concept that I want you to understand here is that all denial of service attacks are about leverage. So anybody taken physics? Like why is leverage important? Or what is maybe the concept of leverage? It's been a while since I've taken physics. So I need to rely on you too. Yeah. So that's good. Makes a hard task easier. A multiplying force. There we go. These are all good. Yeah, the quote of give me a lever and I can move the world. So kind of you can think of it in a lot of different ways. But yeah, the important thing is you're using something so that you get less effort and more outcome in some one way to think of it. So what we're going to think about here for all of these denial of service attacks is what types of resources does it take us to do this attack and what resources does the victim have to use. So a sin flooding is very, very easy. So we have our victim will say that they're at IPV. And we just start sending packets from let's see we'll call it IPA first destination IP IPV. And then let's let's see source port 8 8 9 9 destination port. It actually doesn't matter. It has to be something that it's actually listening on. So let's say it's port 80. And I'm going to send a sin packet. So okay. Let's think here for a second. So I send this packet out. It's going. All right, let's we don't have to give all types of terrible quotes that are not actually correct. You can Google on the internet for those bad quotes. So let's go with a sin packet. So we send the sin packet to V. Now what's V going to have to do? What's the packet that V is going to send us back. So if it's listening on that we which let's say we know it's listening there. So what's the source IP going to be? Yeah, IPV destination IP IPA source port 80 destination port 8 8 9 9 sin act. And I'm actually missing something here. I need a sequence number 1234. Cool. And then I also need a let's see sequence number. I will do 432 1 and act number is going to be 123 5. Cool. So the victim has to send that. And now think about if you're writing this operating system, right? So you actually have to now be handling and writing this TCP three way handshake, right?  So so for V, if we think about the operating system, what does it have to store in order to be able to reply correctly to that third act packet that it gets back? Yeah, it needs at least the source and destination IP, also the ports, right? So it has to store at least those bit of information because it's a the four tuple of the socket. What else does it need to know? Yeah, the sequence number exactly needs to remember its sequence number that it chose. And it needs to remember the acknowledgement number of the other side, right? So if you think about it, essentially, all of this information has to be stored inside the operating system of V until it gets an acknowledgement number. Now, again, because of the way we talked about the way networking work that networking works, the IPA that initiated this connection could go away at any time. So V doesn't know if it's ever going to get that final acknowledgement back. So it needs to store that information in the operating system for some period of time. But so if we think, okay, I can so let's say this is the attacker, the attacker can send one packet this starting sin packet. And it can cause the attacker to store all of this data on their system. And the cool thing is as an attacker, I don't actually care about creating this three way handshake, I'm looking for that lever. So the lever is I can send one packet. And I don't have to store any of this information. So I store on my side nothing. But the other side, I force them to store at least this much information in their operating system. And another thing to think about if my goal is just to have them store this information in their operating system, do I care about replying to this packet? Or do I even care about getting this packet back? So then who says I have to use my IP address? I can use anybody's IP address, I can use IPB, I can use IPC, I can use Google's IP, I can use any IP I want. Yeah, and this is a great point, Marcus. So the, yeah, the now here, we actually, it's even better if we're able to hide our source IP address, because now we don't want people to know exactly where we're coming from. You could use the targets IP address, I'm not sure how that would work, it may drop that, I'm not sure that's a little weird, I probably wouldn't use that. And so this is the goal of sin flooding is to basically send tons of these packets, because every packet you send, and this is the lever again, every packet you send cost the attacker nothing, but it forces the victim to store for every packet this information. So if we can send a bunch, and if you think about an operating system, right, is kind of running under here has its own memory space. So it, you can eventually fill up all the memory of the operating system. And then at that point, the can't accept any new connections, because it says, Hey, sorry, I don't have any more room. Yeah, so it's similar to an ax storm, but it's a deliberately caused sin flooding. So you can think of a sin flood. You can so it depends on the operating system, usually they would not, it really all depends on the on the specifics of the operating system. So usually they don't use like a ring buffer like that because they each, because the way I think it's in the specification of like when you send a sin act, you need to wait a certain amount of time before you get an act. And then you can drop that, that packet, or assume the communication is closed. So if most of them are doing that, they're all waiting basically like 30 seconds or something. Cool. So this is yeah, this is a. And so this is kind of a really common and kind of first level sin flooding, like denial of service attack. Yeah, and the other goal is, as you're doing this, if it's a big server, it's just the fact that now you're filling up all of the resources of this computer with your kind of fake traffic, so that when somebody else sends a sin packet that says, Hey, I want to talk to you. The machine doesn't respond or drops it basically. So yeah, this is a and kind of all different types of denial of service attacks rely on this notion of this lever of the fact that you, it costs the attacker nothing and it costs the victim something to respond. So yeah, by doing this, I can generate a bunch of traffic and cause that traffic to turn into resources that are stored on the system. Okay, so then now we can maybe think a little bit about prevention. So how would we prevent something like this? Yeah, so it's, it's okay, lots of different ideas. So we can try to detect it. But this is actually the key problem of doing a lot of network defense things. If you try to detect it from a specific IP address, what if I'm changing my IP address? So it's always random. And another thing is how do you detect the difference between a sin flooding attack like this, and just let's say your service becomes all of the sudden popular. What's the is getting reddited a thing, it used to be called getting slash dotted when a bunch of people were sent to your server, but I don't know if Reddit has that poll. Hug of death. Okay, there you go. Yes. Yeah, or exactly, that's a good one. What if they choose actual IP addresses of your customers, and now you're blocking those IPs from getting there? Right. So yeah, you can, yeah, because you control this IP address, so if you just tried to block based on IP address, a good attacker will always be changing this IP address. So you wouldn't be able to rely on that. So maybe another thing you could do is maybe try to detect some feature of these packets that make them look more suspicious.  Maybe their sequence or acknowledgement numbers are the same. The problem though is pattern or timing of them. It's really difficult because the timing all you have is one packet. So you need to decide, do you send this packet to V or not? Now machine learning is terrible for stuff like this. People try to use it all the time. And as you've seen in, if you've seen any adversarial machine learning stuff at machine learning systems are very easy to be controlled by an adversary. And if you think about the only things that have to be here in this packet are the destination IP address and the destination port. These are the only things that absolutely need to be in this packet. Everything else can be randomized. So how do you make a machine learning feature on something like this, where you have such little information? That's not to say that people don't try, but a dedicated attacker should be able to do this in a good way. Now, some things to think about. So somebody said, well, let's make the buffer larger, right? Let's like increase the size of our servers. And you can see that this happens basically over time. So machines get bigger and bigger. The operating system has more and more room. So it's harder, especially from one machine to generate the number of packets that you want. Because if you think if I'm sending all of these out from one machine, I may have a fixed amount of bandwidth that I can send from. So one thing I could do is I could take over a bunch of machines, have them all be sending, using their bandwidth to send different sin flooding packets to the victim and try to increase the amount of resources that I'm using, right? So if I can use 10 machines, I've now increased my capability by a factor of 10, 100, 100 times 1000, 10,000. And you can actually go easily rent.  So this is when, so this is kind of the idea of the difference between a denial of service, DOS versus DDOS, right? So a distributed denial of service. Yeah, so this notion of the problem is the handshake, right? And the problem is if you do a handshake on a different machine, well, now you're basically targeting now that machine, right? So this actually could be one idea is maybe get a huge freaking machine that does all of the TCP handshakes first and then only things that make it through, it goes out. But again, that then becomes your weak link that you can target and overcome. Yeah, so one thing, okay, Skyler has a good point. So one thing would be reduce the acknowledgement time after a SINAC is sent. So you could say only store this. So if I was storing it in the operating system for 30 seconds, say I'm only going to store it for maybe 0.5 seconds. And that could then have follow on false positive effects where now you're timing out good connections from people with slow responses. So think about people who are using like the internet in rural areas or on dial up, who it may take longer than 0.5 seconds to get there or satellite where that's a great point you literally your packet has to go from the earth to a satellite and back for it to travel in different places, right? And maybe you are willing to make that sacrifice and that would be fine. But if you're under a constant denial of service, it's probably not in your best interest to especially if you have customers in that area. So yeah, that's definitely a one thing to think about. So what about if we wanted to get rid of the fundamental problem, what could we do? So what's the fundamental problem here? Exactly keeping track of this data, right? The problem is actually storing this data. So what if I just didn't store it, right? Well, it'd be a little bit of a problem because then I need to know when I get this acknowledgement packet, the AC packet back, right? I need to know, is this a proper acknowledgement packets? But we can actually use a, yeah, so let's look at some of these things. I think we've already talked about a lot of these, we can try to filter, we can try to increase the length of the half open connection queue. That's what we talked about here, reduce the sin received timeout or the AC received timeout. In this case, I think it should be we can drop half open connections. So this is the idea of like a ring buffer, basically, of dropping old connections. And we can try to limit maybe from a specific source. One super interesting idea is to use what's called sin cookies. So this is in an RFC. So this is a really important problem that basically has a whole RFC dedicated to it. So you can go here, read up on all of these different kinds of techniques and solutions. And basically, this really cool thing is essentially a sin cookie. And the details aren't super important. But the idea is, can you make a, so if we think about it, let's see, conceptually, we get a, we know we get a sin packet first, right? So the attacker gets to choose the source IP, the destination IP, the source port, destination port. And the sequence number, the only thing that we get to choose is the acknowledgement number. But basically, the idea is, can I encode information into this acknowledgement number, such that when I get it back, I can verify. Yes, I sent this packet, it's from this IP, this IP, this port, source port, destination port, and this sequence number. So it's a really cool idea to say, okay, I'm not going to store any information in my operating system. I'm going to encode all of this information inside this acknowledgement field so that I can verify when I get that back that if it was correct or not. So, and they also encode, yeah, so anyways, I'm not going to go into the details of this, but it's essentially a hash of a lot of different types of things that allows an attacker, allows the server to not actually store data and store information about the connection, but to basically put that in the packet itself. And then when it gets a response, it can check that. So this is kind of a cool, very clever idea to like attack the root of the problem that says, well, the problem is, the attacker does no work and we store data. So how do we make that work? So, and let's actually talk for a second. Okay, cool. Uh, yep. Cool, cool, cool. Anyways, that's always done on the client side, the on the and so I guess the key question is, so what's the difference between like a sin flooding attack? And what if me? So let's say this is a Eve our attacker. What if Eve just makes, let's say connect, right, just connect to this machine, do the three-way handshake, but just do that a lot. So what's the difference between that and a, yeah, why is it detectable? Or what about it makes it detect detectable? Yes, the IP has to be the same, right? You have to receive packets back, and you have to reply to them. So you can't. So and if you think about it, there's no lever here, right? You have to on your side in order to establish a connection, you have to store just as much data as the server, right? So typically we think a server will have a lot. Yes, a very sad lever, right?  Yeah, it's, it's actually a one to one lever, there's actually no lever, you're getting zero leverage and advantage. Because all the data that we're sending to the server, we have to store the same amount of data for TCP connection as the server does. And so if our machine was just bigger than the server, then yes, sure, we can take it down, but that that doesn't really help the adversary can just get more machines. Now, maybe I can then take this idea and extend it, I can maybe get leverage then through my botnet. So then maybe I leverage a denial of service to just make a ton of actual connections to the machine in order to take it down. We see, let's see. So yeah, so the idea is so we can get a lever through the botnet, but still, it's not going to be as effective as using something like sin flooding, or something that has a built in lever to it, that amplifies traffic, basically. What can you be more specific? What do you what do you call an amplification attack? That's a little bit different. So the other thing to think about, especially about denial of service attacks is, so we saw like, specifically, so for instance, specifically, we were targeting here the number of half open connections that an operating system would have in its memory. And that's the specific resources that we're targeting, we can also target, and this is basically, you can then extend this idea. So you can now think of, okay, for a denial of service attack, I need a lever, and I need to target a specific resource. So it could be maybe just memory of the server. So this is actually a really interesting one, memory. So we can maybe force the other side to send us data, but never acknowledge it. So if we think, if we're transferring a big file or some part of a file, an application will send data to the OS to send from one side of the TCP connection to the other. And we just never acknowledge that we saw that data. So we just say, Oh, no, that data is somehow getting lost. And if I just do this a lot, I can force a lot of resources and memory to be stored on the system. Similarly, with so most, for instance, like a web server, most web servers use some kind of process pool. So there's a fixed number of processes that will handle incoming connections.  And I overflow the number of processes or threads that they have to manage that. And they can't get any more. And I just keep those connections open for as long as possible. You can target how much memory there exists for socket descriptors, or in most operating systems, there's a limit on how many sockets you can have open. And so you can actually hit that limit. So then we can go and talk about for a second, this denial of service reflection attacks. So you can think of there's a couple ways I can take down V, right? Yeah, so there's a couple ways I can take down V, right? Essentially, we've talked about I can take over and make it use too much resources internally. But what if so what is actually so I just drew like a line here, but what actually is this line, this line right here, this connection from V to the cloud. Yeah, I mean, we don't know exactly what it is. But it's some kind of physical connection. If we think about the TCP IP stack at the bottom layer, it's some sort of physical connection. And there are hard physical limits on how much data can go through those. And also somebody mentioned hops, there's also a switch here, right? There are physical limits to how much traffic can go through a switch. No, not cut the wire overload the wire. Let's see. I don't think there's enough slack free cases. Nope. Okay, there's no way for me to get this in frame. No, impossible. Okay. So what we can do is we can actually overload this wire if we're able to send. Let's think maybe it's we'll go with an easy one. It's just like a gig. Oh, move the camera. It's attached to the to it. So anyways, it's a it's fine. It's just an internet cable. But let's say it's like a gigabit per second is the Gbps is the capacity of this wire right here. So if we're able to send more than a gigabit of traffic through there, and it doesn't even have to be traffic that V can respond to, it could be garbage just as long as we saturate that link and send more data that can physically go through there, it will appear to be off because nobody else can talk to it. Even though V itself, we haven't attacked any resources with V. So how to do this we need basically a very large lever. And there are a number of different ways there've been. I think NTP had a amplification vulnerability. So the network time protocol is one way. There are DNS. Yeah, the limit of the internet cable, you can look it up, I don't know off the top my head, I just made up something. And honestly, probably your switch would probably fall over before your cable itself, but we'll target the cable right now. And so you can pick either of these the NTP one was pretty egregious. I think it was something like 1000 to one. The basic idea was NTP is I believe a UDP based protocol. So what an attacker would do is basically send, let's say five bytes to NTP server spoofing source IP victim. And then the NTP server would send let's say 5000 bytes to to victim to the victim IP as a response. And in this way, so basically, I can if I have a, let's say an outgoing connection if Eve have an outgoing connection that's what would that be? Let's say 0.2 gbps. So if Eve can send that, then by sending Oh, this is 1000x. Yeah, I guess it doesn't even need to be that much. So basically, if Eve sends five bytes, so Eve now here has a 1000x lever. So Eve can send five byte packets to this NTP server. And then it will send 1000 times that amount of data to our victim, we can easily overload a one gigabit per second connection using what we have here. So in some sense, I think how we originally got here was the cookie approach has actually no relation to most of these amplification attacks. Because with an application, you can just overload the physical capacities of that switch to deal with it. Yes, it assumes the NTP server has at least a one gigabit per second, or what you do is you just find, you know, X amount of NTP servers on the internet and use a bunch of them to reflect traffic all towards the victim. Yeah, so super cool stuff. So this is kind of another then state attack to take advantage of and and attack the state like the capacity of your physical wire, which is pretty cool. Yeah, so there have been a lot of modern attacks, I think they can get up to I want to say like 20 gbps is like some of the latest ones, somebody wants to look up like DDoS capacity attacks, and maybe more than that, I think Krebs on security got hit with one a while back. But if somebody looks up that number and throws it in the chat, I will update that. But yeah, attackers by taking control of a lot of machines and using different types of amplifications, they can cause these insane denial of service attacks. Oh, 1.3 terabyte. Wow. Okay, so yeah, that's a lot. Yeah, that is very large. Right, you can actually take down a ton of systems there. And, you know, even if and this is the really difficult thing of even if you technically if the victim technically in their network could handle it, it could be something upstream that fails. Wow, that's crazy. Was that the one with cloud fare cloud flare? Do you remember? I don't know. Anyways, oh, it was GitHub. Cool. Oh, okay, I see 1.3 terabyte per second for GitHub. How does cloud flare work? That is a great networking question. At a very coarse grained, they essentially try to have boxes. So we talked about like traffic has to go from you to your ISP to other ISPs to the ISP of the target and then the IS their machine. Basically, they try to have a server in everybody's ISP, so they can get traffic and things to you very quickly. Cool. Yeah, cloud flare, the other one that's really big that you probably don't hear about very much is Akamai, which like a content distribution network type thing, which does this similar thing of like having, I think Netflix does this too, basically, where they try to have servers in as many local ISPs as possible. So when you're streaming a movie, it's coming as few hops away as possible. Okay. Yeah, awesome. So there's a lot of stuff that you can play with. And yeah, okay, cool. So then, so we're kind of actually towards the end of our network stuff here. So then we're going to move on to binaries. So we can kind of talk a little bit. One concept that comes up again and again in terms of networking is a notion of a firewall. So if we think, actually, we'll do some other stuff that I hadn't scheduled. Okay, so we have all the machines. So we have our local network, we have our gateway. And I'm going to call it G. No, that's bad G. G close enough. At some point, I'm just gonna give up our gateway. And then we have basically the outside world. So then we have now our nice cloud that's the internet. I swear I'm getting better at drawing these clouds. So the core idea of a firewall is, oh, okay, cool. GitHub does do use Akamai cool. And then you can check out this link to learn more about it. Oh, it's memcache that they targeted interesting. So the idea is we want some kind of mechanism from a security perspective, we want some kind of mechanism in order to and I'm going to draw it like this.  So for instance, if we wanted, let's say for, yeah, okay, this is a good example. Okay, so let's say this is my ASU. Let's say we're ASUs network, this is my ASU. And let's say this is grade database. G is our gateway. Okay, so this is so let's think so like my ASU right so the network is obviously much more complicated than this. And now we'll go with my machine. I don't want to target anyone else. Okay. So let's say that this is my work desktop. So we're all basically on ASUs network. So if you think about it from an external, no, it's more like, actually, the ASU network is one of the most insane things it's has we have at least I think 100,000 devices on the network plus probably more I think it's probably more like 110 120 with all the research machines and everything. And on top of that, you have students and their devices leaving every four years. So a quarter of our devices have turnover and churn every year. So it's I would not want to be in charge of defending this network. Yeah, it's a crazy network. You think about most companies right the turnover of most companies is not 20 to 25%. But by the nature of colleges, hopefully a quarter of you are graduating every year. And so that means new people are coming in every year as freshmen and so you get this massive turnover. Anyways, okay, so if we think about this. So from the outside, what should an outsider be able to access in our network? My ASU exactly, this is the only thing we want people to be able to access. We don't want people to directly access the grade database that would be silly. We don't want people to directly access my machine. Right. And so what we can use is this firewall, and we can plug in and program rules into our firewall that says from anybody coming from the outside, they should only be able to go to my ASU. So now I'm going to switch to select the firewall policy would state allow to IP my ASU port AD TCP. No, we haven't covered that I may cover it right now we'll see how much time we have. Right.  Now I have another problem of then how do people like how do I get out from the network? Right. So I could maybe say, oh, also I need to allow outgoing traffic. And you can spend a lot of times. Yeah, so 443. Yeah, you've already figured out that this is insanely complicated. And so, you know, we're just covering the basics here because you can go insanely deep into firewalls, you could then say, as as you keep using a firewall and you accumulate all these rules, what happens if I have conflicting rules? How do I specify what to block? How do I how do I express different types of things? Like for instance, like allow any outgoing traffic. That's and, you know, kind of an interesting thing. Anyways, and the other thing is, how does this actually prevent me from accessing the grade database directly? Or let's say, I don't want to pick on any of you directly. I'll just call you student one. So this is your student one machine. What's to stop you from accessing the grade grade database connection? So the interesting thing about allowing outgoing is how do you determine what's because if you think about it, when somebody contacts into my ASU, my ASU will have to reply. So how do I allow that reply? And how do I allow Adam D to initiate outgoing communications? Yeah, so other things I may add another firewall here, I may separate my network out again, this isn't a network networking security class. So we're not going to go into all of these details, but I want you to be aware of these concepts when you're talking about firewalls, right? And these types of things. So being aware of what they're made for, what their usage, they can also do things like, so this is maybe why so they can maybe block ICMP, we talked about that, right? Of what if you're not able to ping a machine or something like that, it doesn't necessarily mean that it's down. It could have a firewall policy to block ICMP messages, all different types of stuff. And this is, we're just, you know, really just scratching the surface here. But it's one of the core components of kind of thinking about the network security of a system. So it's important for you to be exposed to it and aware of it. I think with everything that we've studied with how the networking protocols actually work, firewalls are not really that specifically complicated. So this is why I wanted to focus more on how networking actually works and what are the security implications here, and then discuss kind of the concept or idea of firewalls. Other types of network security mechanisms are, and so again, actually, if we go back here for one more second, we can see again, this notion that we talked about earlier in the class of the differences between mechanisms and policies, right? So a firewall is just a mechanism to try to enforce a network access policy. But you need a policy of what to block and what to allow, right? So this is again, gets to that notion of you need a policy of what should be allowed and what should not be allowed. So yeah, the other interesting things, you know, if you think about the ASU network, there's actually a VPN server in here. Oops, that doesn't look right. A VPN server in here, that the firewall allows you access to the VPN server that then routes your traffic. So this is actually how, for instance, like I could get to my desktop from here is I VPN into the my ASU network and then my traffic comes out as if it's inside the my ASU network past the firewall so I can access my machine. But anyways, all kinds of stuff in there. Other types of systems like intrusion detection systems. So this is kind of an another type of thing, where it's a mechanism, right? So the mechanism is you want to and I will draw a that's really bad. Let's say this is a magnifying glass. You know what, I'm just going to do this and do IDS. And it's kind of an so okay, yeah, so for firewalls, yeah, if you think about it, the year, it's a whitelisting versus blacklisting thing. So whitelisting is much more secure, right, because you're only saying what things should be allowed. So you want to deny everything and only allow specific things through.  And this is, you know, using exactly what kind of tools we saw TZP dump all these kinds of things, monitor the network traffic and try to determine either evidence that we've been compromised, or that were under attack, right? So those are things like we saw an intrusion detection system can detect that you're sending port that you're being port scanned, or they'll have other types of rules. And they'll be able to even identify, hey, somebody's trying to exploit some vulnerability on one of our systems. Maybe I should flag that. It's a very complicated area because all you have is network traffic. So you are at least in this case, without thinking about the host, there's host based intrusion detection systems, all kinds of stuff. But you're trying to determine if you've been attacked or not. And more fundamentally, you're looking at packets and trying to determine is this a benign or malicious traffic. So you need now a policy of what to detect. So I will say if you want to go play with this, you can go is an open source is an open source intrusion detection system that you can actually just install run on your system, it will look at all the traffic and see if you've been stuff. And if you've been attacked, I will say snort it can be very annoying because it has a the default rules are tried to the policy of what to detect has a lot of things that are in there. A cool distinction between so and the key thing here is the difference between detection and prevention. So an intrusion detection system will just basically alert that, hey, I think I've seen something bad here. An intrusion prevention system will actually block your access. So it will say, I'm going to kill this connection as soon as I see something bad. So yes, funny story, I'll say very briefly, one of the CTFs that I helped admin and run was the I think it was 2011, I CTF, where every team connected into a VPN network. And what we had is we had snort running on every incoming connection. And as soon as we detected a snort rule violation, we block their connection for five minutes. So what happens is team somebody on a team would be port scanning stuff, it would trigger snort, and then we cut their connection for five minutes. So yeah, it's a, you know, like you can get really into these types of systems, there's all types of commercial tools, we're not going to talk about them, but you definitely know enough to understand how they work by looking at this network traffic. And so basically from here, there's a ton of different areas in order to there's a lot of different ways that you can take and go into network security. And there's a lot of research here. So for instance, one of the areas that we do research in is software defined networking. So the idea is that if you've ever like programmed switches or done anything like that been into like Cisco or all that stuff, it's kind of a real pain in the butt to configure all of these different switches. So the idea is make the switches really dumb and have a central machine that controls all the switches can program rules and has a global view of the entire network. So for instance, in the context here, one of the really interesting things that we've done with this is rather than have a firewall just on let's say your the entry point of your network, with this, you can essentially put a firewall into every switch of your network. So every switch can be enforcing your firewall rules, so that you can do things like enforce Hey, Adam D should not be able to talk to the grade database, right? Only maybe my ASU should be able to talk to the grad grade database or whatever front end there. And one of the really interesting things about software defined networking is like Google uses this in their data centers, and they took their network utilization up from like 70% to like 99.9% or something insane like that. So they're getting a lot of benefit from using these kinds of techniques. Like we talked about, there's a lot of stuff to do in firewalls, analyzing them, verifying correctness, all kinds of things intrusion detection systems were actually really funny. They were a really big research area in like the late 90s, early 2000s. And people it's basically just a very, very difficult problem that's really hard to solve. So it kind of went away. And now it's back under the guise of advanced persistent threat detection. So you can think about intrusion detection systems, like how do you take if you have an IDS here, and here, and on this machine, how do you take all those logs, aggregate them, understand what happens? It's kind of a crazy thing. Other things that you can go look up at is IPv6. So one of the key things that actually it's kind of insane that we have didn't talk about. So we talked about IP addresses. Right. So how big was an IP address? How many bits? Yeah, 32 bits. So they're going to be two to the roughly two to the 32, which is like 4.2 million. That's actually not enough, which seems kind of crazy, right? Oh, is it billion? Okay. Right. And actually, so that's not even enough, right? So if you think about if you wanted every person to have an IP address, that's actually not enough addresses. And for various other reasons. So IPv6, they move to I believe it's 128 bit addresses. Can somebody check me that that's correct? Yeah, I thought it was I couldn't remember exactly. Two to the 128 gives us Oh, is that what it is? Well, yeah, so a ton. So that's 3.4 times 10 to the 38. So three, three, followed by 38 zeros. So there's been all kinds of stuff we basically have a tons of IP address range now in IPv6. But the problem is the transition has basically been very, very slow. And it looks does look very ugly. So looking at I'm very much used to IPv4 addresses, IPv6 addresses uses kind of similar to kind of similar to Ethernet addresses uses kind of the colon notation with different aspects here. So yeah, so anyways, you can go learn more about IPv6. It has actually the same kind of RFCs that you can go learn about. I'll definitely say I'm not an expert yet. But it kind of is the future and we're slowly over time shifting more and more over to IPv6. Let's see. IPsec is a basically a technology in a way to put add security into the IP layer. So for all of those reasons that we talked about that, the IP layer does not provide anything in terms of authentication, integrity, reliability, anything like that. IPsec tries to address some of those so you can go kind of look that up more in there. Cool. And then I think with the Oh, yeah, I didn't talk about that. 802.11x. Let's see. And now I'm going to write down anything else that anybody wants to learn about in the next 15 minutes in regards to networking. So you have somebody mentioned 802.11x, which I can talk about Nat, which we talked about. What is networking, you should start at the top and relearn it. Cool. Okay. So is it 1x? Yeah. So we talked about this a little bit. So 802.11x is basically solves the problem of anybody being able to plug into an ethernet port. So 802.11x allows you to do basically port based authentication. So we talked about my beautiful design of a switch. So you have different ports in a switch. And it actually allows you to authenticate to a remote system. So when a cable is plugged in here, that's not good. When the cable is plugged in here, this can actually be authenticated. So we know that this is somebody inside of our organization and not somebody external. So that's kind of the high level version there. Nat, so Nat stands for, and actually Nat is probably the biggest reason why we've been able to stay on IPv4 for so long. So if some of you right now would go open up a terminal, run if config or ipconfig. If you're on Windows, I think ipconfig should work. If you can run that and tell me what your IP address is. So we know there's some special IP ranges, right? So we know 127 0000 slash eight is local network. Let's see, have some other ones <IP_ADDRESS>. Same.1. Let's see, somebody else is 1.215. Think anybody else 015. That's good. Anybody got a 10. something 015. I can show you mine <IP_ADDRESS>. So this is actually a little weird. Can somebody send me so if you look at like mine, right, you can see my net mask or my broadcast. So my network, I'm on 192. So if I go here, I'm on slash 24. Anybody else here? Is it on something? Can somebody like who is <IP_ADDRESS>? Could you show me your what's your net mask? Oh, what is that a slash? I don't even know what that is. It's like a slash 30 or something. So I'm going to go out on a limb and guess this is a slash 24 and this is a slash 24 as well. Let's see, can I, okay, I'm going to use you for a second Emily. Okay, so why aren't Emily and I on the same network? This seems kind of crazy, right? We just learned we have IP addresses. So we have I have an IP address, I have a net mask, I have a gateway which is 192.168.01. So how come, so how come I can't ping Emily? Yeah. So exactly. Okay, so now we've run into this interesting thing. So there's a couple things here. One is we've actually have other types of special IP ranges <IP_ADDRESS>. I believe it's slash 16 is private network. And <IP_ADDRESS> slash eight is also a private network. There's another one, I think it starts with 172. That is another private network. I'll have to look that up and figure that out. But so all of these IP address ranges, so there we go 172.16. I don't remember the range there. Do you remember is it to 32? Yeah, whatever 12. Okay, cool. Awesome. Okay, cool. Thank you. Okay, so there I get local network, private network. So these are all different size networks. And they're guaranteed by the RFC to actually be private. And what that means is not globally routable. So your feet, you can be free to use these IP address range internally. And no, no one will be able to route to that. So this is why just so happens that Emily and I have the same IP address range locally inside of our local networks. But how does this actually work? Because now, if I wanted to ping, and we've actually seen this before, I didn't talk about it. But if I ping <IP_ADDRESS>, and I run TCP dump. So if I run this, I see and we actually captured those packets, right, we saw packets that had source IP of my now we know internal private IP <IP_ADDRESS>, and two <IP_ADDRESS>.<IP_ADDRESS>.8.8.8 is able to magically reply to me at <IP_ADDRESS>, which seems insane. This should never happen because I just said this is a private IP address. No one can actually talk to this IP address. This is why I was you're fine posting this IP address here in this channel, because nobody else can ever route to that IP address. And it's all due to that. Okay, so how does this work? So I'll draw me. So I'm here on this network. I'm connected to my a switch, which is connected to a gateway that also does NAT. So gateway, and it has its, and this is to my now my ISP. Let's see what I want this to do.  I mean, it's usually all in one, right? So usually this switch and this gateway are all in one. But it you have a public IP address that's given to you by your ISP, right? This is what we've been talking about in terms of IP address. This is the public IP address that's not in one of these ranges that people can actually route to. And oftentimes you actually internally don't even know it. So, so what happens is your gateway uses this protocol called NAT to translate every packet that goes outside of your network to this internal IP address. So what does this look like? So let's say we just saw an ICMP packet, we'll talk about it at the IP level. So I have we know that I will have source IP. So now I'm saying this is my internal IP address. So this is IP internal a destination IP. I want this to go to <IP_ADDRESS>.8. And I'll just call it an ICMP packet. So this packet gets sent. And we've been studying this for a while. So we all know exactly what happens. We know how the next step delivery we know that my machine has to to knows the gateway. So it has to use ARP to figure out the Ethernet address of the gateway sends the packet. So this packet goes from me internally to my gateway. The gateway gets this packet says where is this packet going <IP_ADDRESS>.8. Oh, great. That's out on this. I need to translate that packet. So before this packet goes out, the gateway will translate it and say, okay, source IP is now it can't use the internal. It has to use the external. And it uses destination IP as <IP_ADDRESS> and ICMP. And then at this point, this is the packet that gets sent out to the world. So that Google can get that. And what the gateway stores is the gateway stores a mapping that says, at least in this case, ICMP to <IP_ADDRESS> back to IP int a so it can translate it back. So when Google gets this, Google will reply destination, Google will reply with source IP 8.8.8 destination IP IP A ICMP. So this gets sent now from Google back to my gateway, the gateway gets this. And then it does its translation. So it that's the network address translation, the t part, and it's going to change this to the internal IP address. And then that is now what my machine sees. And that's exactly what we're seeing here in this example. So we're seeing ICMP, echo requests and replies that use internal IP addresses, which the gateway has translated for us using that. And so, yeah, it's really the terminal color scheme. I can't remember. I think it's like Dracula or Dracula or something. I don't know, I can post it later if somebody asked me in Piazza. So yeah, so and basically your router is doing this for every single packet that goes out. So it has all kinds of cool stuff to be able to map this it will change different ports to know what ports to come back as anyways, network address translation is super cool, because it's doing all this work. And one of the super interesting things, and this is very cool, is how does anybody outside so let's say there's, we'll go back to Eve. We go back to Eve. And we say, okay, let's send. How can Eve send a sin packet to me? So let's think about this. So Eve would need to send a packet that went basically, we'll call it ICMP for now. Doesn't really matter. But let's say so source IP is IP Eve destination IP address IP A sends this packet out. Eve sends this packet gets to my gateway. My gateway says, Oh, I don't have any way to translate this. I'm not expecting a packet back in for internal A. So I'm going to drop this packet and it never sees it. So I basically can't and that's why so people are talking about port forwarding, right? So this is why if you want to run a, I just would put FW, this is why if you want to run like a something internally inside your network, that you want people to be able to connect to it, you can set up your router and say when you get it essentially a sin packet on this specific port forward it to the Xbox and that's talking to the NAT translation to do that. There's also, if you really want to look at this, there's a really cool protocol called stun, which is how can you do so if you and I are both behind NATs, and we want to do a peer to peer connection, how do we set that up so that we can talk to each other. So there's a whole protocol of cool tricks to do that to trick your router into doing this. But anyways, this is kind of the, I guess, short ish, but was kind of long explanation of NAT and network address translation. So one thing I will tell you is you can go to, you can go to ipchicken.com that can tell you your IP address and you can compare that with IP addresses you put in here. I would not personally share your IP address just, you know, you never know, keep that private at least a little bit. You can check that out. And so thanks everyone, that was a great class. And on Tuesday, we will start with binaries. We'll get to binary hacking. See y'all. Be safe.


There's an old Chinese saying and it says, the temptation to give up is greatest right before you're gonna succeed. So do this, when you emotionally feel like giving up, I promise you, that means you're closest to succeeding. It's crazy, it's like you're walking through your house.  And right when you get to the front door to open it, most people give up right there. I read a report which basically said 70% of people give up after one obstacle. 70%, anything they do, anything. Trying to build a business, going to college, whatever. The second thing is, after two failed attempts, 90% of people have given up and only 10% of people stick after three times. People wanna learn lose weight, they go to the gym, then they'll lose weight right away and 70% of people never come back. That's why gyms make a lot of money because they have small spaces and they can sell 1,000 memberships because most people sign up for a gym, go once or twice and then give up. Same with making money.


Hey guys shiver 1000 here today, we're gonna be setting up a teepee tent Stay tuned Okay, guys what we have here today Is a teepee tent? That's right teepee teepee tent it's from Mozart trail I Know whatever it was. Oh, you know, they're supposed to be junk just like Coleman's their junk and well You're hearing that from these guys that go out and they spend five six hundred dollars on a tent That's going to do pretty much same thing this does I've never had a problem with those or trio my favorite used to be Coleman but now it's my second favorite I like both of them I've never had a problem with either one of them and no I am not being endorsed by either one of these or I'm Not endorsing them or whatever you want to call it I'm just giving you, you know, this is my preference from what what I've you know I've learned over several several years of camping. It's always been a Coleman or Ozark trail I've never had a problem with any of them If you take care of them like they're supposed to We're going to water seal it with scotch guard It's for tents and stuff. So we're gonna use this I've never used this on a tent, but I'm sure it's going to be fine. Also guys you can also use Actually like a cooking spray stuff like that Will work as well, but I just use that kind of stuff But yeah, you're gonna want to do that. I'm looking at about an hour worth the daylight now hour and a half tall So we're going to set this up, but right now it's doing unboxing, all right, of course just like any tannic comes with a carry case and No, I love the packaging the packaging is so soothing Some of you guys might get that so Apparently she does monkeys over there. She got some barbecue barbecue guy came to my work today We have an owner's manual That's where that goes So You guys hear that so I May need I've never set up a teepee tent before I built teepees Out of tarp and things like that I've Set up, you know actually real teepees You know it would stick great big things, but okay, so here's what we've got here By the way, this is what 50 bucks, huh? Yep, what you mean ribs and chicken ribs and chicken and corn Okay, there's the tenant cell Here's the steaks and these must be the poles This is one of those Things you hang inside, you know, you can put your your things in and it zips up so Pretty neat like I said the steaks And huh And no it goes on the inside so if you waterproof your tent you shouldn't have to You That's waterproof you should be okay, right? It's like your house is waterproof You know I keep in the water I Understand what you're saying do and melt your Moisture and stuff like that if it is rainy and you feel like it's gonna get you're gonna get a lot of Moisture in the air just you know bring a ziplock baggie or something of that nature Okay, so All right There's a baggie This is to put your your tent poles in so I'm gonna turn you around here We're gonna set this up together All of us We're gonna set it up right Right about here. Okay guys, so now We're gonna untie this I Know you can't see me, but I'm untying the tent All right Now I have this untied Let's roll it out at the the two furthest points is 11 foot by 11 foot so You can it's seven person which is plenty big enough for me and her But it's seven person total now remember they don't add all your gear and stuff like that So if you're looking for a tube two people you need at least a four-man tent if you're a single person and You know, let's say you're going on a weekend then you might want to consider Excuse me a two-man tent For the the fact that you know, you got to have room for your gear in case it rains If you're just hiking doing an overnighter. Yes, single person for single person is fine So See what we got All right Huh? I told you it was big. She didn't think it was gonna be very bad Huh? If you can fit to our beds queen size honey So if you can fit two queen size mattresses in this thing that gives you an idea about how big it is so now I'm gonna put the stakes in it In the sides here. I'm not gonna bore you with that.  It can still go another notch. Sorry See till that pops out both of them just like this and then it can still go another notch to tighten up so and you can Tie your lantern or Whatever around here. It's seven foot nine inches seven foot eight inches tall something like that it does have four windows and I Decided on this one for practicality because it's big enough But also the height here in Florida. I'm already getting skews in there. See you guys Here in Florida gets hot. So the height the higher it is the better and we've got the three vents up here So heat rises so it'll keep hopefully at night. Most of the heat will be up here and we we can have our four windows open Just like sorry just like this and then Here is the door like I said, it's only 50 bucks. Well, you want for 50 bucks. I think it's cute. So And there's the door fold back zip her up So there's what we're looking at give you a whole view. So we have a teepee We have a teepee. Yay Hi, so I'm gonna zip that up and I'm gonna spray it down with this scotch guard here And I'll get back with y'all I'm gonna do is I'm gonna spread kind of heavy around the seams They do have a seam sealer too, but I'm gonna spread kind of heavy there and then around through here Just give it a light coat until you see it's misty Looks like that pole needs to be more in the center, but it's okay first time either one of us has set one of these up So Usually it's a tent, but it's kind of cool two poles. There's not one in the center It's awesome. So I'm gonna get back with you as soon as I scotch guard this So stay tuned Okay, guys, so there's our tent I Use the scotch guard all you do is spray the seams and once you get the seams sprayed real good Just spray it like you're you're spray painting something that scotch guard. I don't know if I like it or not I went through two cans. They're kind of small, but The last stuff I used I forget what it was Was regular a tent sealer There's like ten bucks a can but it was a big can and it did a six person tent Which I'm sure would have done that whole thing It doesn't spray real good you can I don't know if you can see some of the Like the wet spots in it there, which they will dry, but that's only telling me that it's it's sealed more In those little areas than the other places by I think it'll be fine as long as it you know keeps dry You know, I'm good with it, you know, so that that's the main thing Let me see tomorrow night Tomorrow we won't go do a couple things Go take a little adventure, right? Yeah, and then Ah Tomorrow night, there you are what we're going to do whoops The live feed yeah, we're going live stream. Yeah, yeah, we're gonna. Yeah, we're gonna do a live video, aren't we? Yeah, yeah, and what we're gonna do Halloween or roundabout Halloween time And do a live feed Story-telling kind of thing. Yeah, but where we're gonna do it at Pick up Mike sure Yes, we are going Roundabout Halloween we're gonna take That boat right there and we're gonna go out on a lake and we're gonna go back in a little Cove after dark, huh? Late and we're gonna give you guys a phone number you can call in and stuff and we're gonna tell stories scary Ghost stories on the boat out in the middle of the lake.  So back in a little Cove. Hopefully it'll be real dark So all right Well anyway guys, thanks for watching there's a little TP I'll give you an update because I'm gonna make some videos tomorrow giving update of how it does and everything We're supposed to get a little rain maybe so hopefully if we do I'll know if that thing If it leaks or not if it does I'm just gonna take it back get something else But anyway, we thought we tried this because neither one of us has ever owned a TP. I've slept in a TP Have you slept in a TP? No, she's never slept in a TP Really, it's just a tank guys, but it's just different. It's neat to go. Ha cool. We got a TP. So anyway guys Thanks for watching stay tuned. We got the water those cadences or something Those are not crickets, honey Okay, she says the crickets they're not they're like a locust type type thing Which a cricket don't do that a cricket chirps, but anyhow, so guys Anyway guys, thanks for watching We'll see you soon catch you on the next one. Shea bear. I'm gone. Remember the myth man legend Shea bear. See you guys later. Bye. Bye