How Internet Routing & Caching Work

DNS Routing and Caching.  How The Internet DNS System Works

The Domain Name System is a modern miracle that allows you to type a URL NAME into any web browser or Email NAME into your software and if everything is working properly you are taken to the website or Email server in a matter of seconds.   

Although you enter a Name the underlying systems of the internet must convert that name to an IP address which is used for routing your request.  The Internet is designed to use "caching" which is a fancy way of saying remembering.  Anytime you go to a location once, the many systems involved all cache the destination so if you ask it again within a day it will remember and not have to do a fresh lookup which makes things resolve faster.


Unfortunately DNS can fail updates or become corrupted within any of the devices that routes your requests.  In most cases even if DNS gets stuck as long as your going to the same destination all will appear normal.  The problem occurs when your Destination IP changes but one or more of the systems within the DNS chain don't get the memo and keep sending you to the old destination or there is a corruption in one of the routing tables. In addition all modern browsers cache files from web sites you visit so they can re-use the files and save time and bandwidth which can  cause a distortion if the content files you are viewing were updated.

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All of the systems that transit DNS are supposed to respect DNS TTL  "Time To Live" and "Expiration" which tells the device how long before they should do a fresh DNS lookup.  Unfortunately when the device has corrupted cache you may experience issues reaching your website or help.domain client area or email problems.

Most DNS problems are resolved by clearing your Browser cache "temporary files" and rebooting your computer, router and modem. 

In rare cases it will be necessary to "Flush Your DNS cache"  and or "Bypass your ISP DNS Server"  or "Edit your computer Hostfile" .  If you are not comfortable with any of these procedures you should  contact your ISP to correct for misdirected DNS.'s responsibility is to insure that your name servers and web/email servers are working properly.  DNS issues due to problems within your network or ISP are outside of the scope of our responsibility.



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