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How are DHCP messages relayed back and forth from that computer to the existing DHCP server?
In nutshell, a DHCP relay agent converts the local DHCP broadcast message in a unicast message by using its IP address as the source IP address and sends the unicast message to the DHCP server.
What is DHCP relay Option 82?
DHCP Option 82 is organized as a single DHCP option that contains information known by the relay agent. This feature provides additional security when DHCP is used to allocate network addresses, and enables the Cisco controller to act as a DHCP relay agent to prevent DHCP client requests from untrusted sources.
What do you think is the benefit of using DHCP relay agents instead of multiple routers acting as DHCP servers?
Each router works harder to manage its DHCP addressing, in addition to the primary function of routing traffic. One DHCP server (router or computer) that is dedicated to the job is easier to manage and more centralized.
How to setup a Cisco DHCP relay agent?
For this lab, my core router is going to be configured to serve as a dhcp server to the two local area networks attached to site1 and site2 routers. Site1 and Site2 routers will be configured as Cisco dhcp relay agents. Their job is to help take dhcp requests from hosts to the dhcp server and deliver IP addresses from the dhcp server to hosts.
How does a router relay DHCP packets when it is configured as a relay?
The IP destination address (in the IP header) is set to the DHCP ‘yiaddr’ address and the link-layer destination address is set to the DHCP ‘chaddr’ address.
How does DHCP send ACK message to router?
As a response to the DHCP REQUEST message, the DHCP SERVER will send a DHCP ACK message to the router, and in turn, the router will broadcast this message on the Fa0/0. Finally, our DHCP Client has its IP address.
How does DHCP client assign IP address dynamically?
To assign an IP address to the host dynamically, DHCP client exchange DHCP messages with DHCP server in DORA process. In DORA process, the discover and request message is broadcast, the offer and the acknowledgement message is broadcast or unicast depending upon the value of broadcast flag i.e.