It serves as proxy that is utilized by the DHCP broadcast messages.
1 You cannot use the DHCP Relay Agent component on a computer running the DHCP service, the network address translation (NAT) routing protocol component with automatic addressing enabled, or Internet Connection Sharing (ICS). For the configuration of DHCP relay, the address of the DHCP server is essential so messages or data can be relayed. The purpose of having DHCP relay agent is to permit DHCP clients and servers be placed on numerous networks. It is not difficult to set up DHCP in a definite network segment. Messages in the DHCP network are IP broadcast and this means that all computers on the sector can respond. DHCP is an acronym used for Dynamic Host Configuration Protocol. This protocol utilizes a relay structure to connect with the DHCP server. It serves as proxy that is utilized by the DHCP broadcast messages. These broadcast messages are important to be routed to different sectors in the subnet. DHCP Relay Agent. The DHCP Relay Agent component is a Bootstrap Protocol (BOOTP) relay agent that relays Dynamic Host Configuration Protocol (DHCP) messages between DHCP clients and DHCP servers on different IP networks. The DHCP Relay Agent is compliant with RFC 1542, Clarifications and Extensions for the Bootstrap Protocol.. For each IP network segment that contains DHCP clients, either a DHCP server or a computer acting as a DHCP Relay Agent is required. You can set the IP address of a DHCP server to which the DHCP relay agent forwards client requests by using the ip dhcp relay server command. The syntax of this command is: ip dhcp relay server ip_address. The ip_address argument specifies the IP address of the DHCP server. A relay agent is a small program that relays DHCP/BOOTP messages between clients and servers on different subnets. DHCP/BOOTP relay agents are part of the DHCP and BOOTP standards and function according to the Request for Comments (RFCs), standard documents that describe protocol design and related behavior.
https://technet.microsoft.com/en-us/library/cc783103(v=ws.10).aspx http://www.qwhatis.com/what-is-dhcp-relay/ http://www.qwhatis.com/what-is-dhcp-relay/ https://technet.microsoft.com/en-us/library/cc783103(v=ws.10).aspx http://www.cisco.com/c/en/us/td/docs/app_ntwk_services/data_center_app_services/ace_appliances/vA1_7_/configuration/routing_bridging/guide/rtbrgdgd/dhcp.html https://technet.microsoft.com/en-us/library/cc779610(v=ws.10).aspx
what is dhcp relay