When I went to install a new set of fancy Arista switches I expected some behavioral differences with other vendors when I got into advanced features like MLAG, VM Tracer, etc. But, DHCP relay agent? What I found was, the default behavior in the Arista software, EOS 4.6.1, meant that the switch employed the use of Option 82 out-of-the-box. In a tcpdump I noticed the switch inserted the relay interface name in the circuit-id (sub-option 1) field. Because I was concerned sending unused options might be problematic, I opted to disable the option 82 push with the no ip dhcp relay circuit-id interface configuration command. I later found that the aforementioned command does not disable the insertion of the circuit-id value. Instead the command reverts a value you may have configured and sets it back to the default value which is the interface name. In our example, vlan10. More importantly however, the Arista switch correctly utilizes the GIADDR DHCP field and inserts the relay interface IP address.
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How to configure the dhcp relay agent on arista?
I have 5 vlans in my network and I configure 3 int vlans with 2 ip helper-addresses.
One ip helper-address for dhcp and the other one for my pxe boot server altiris.
The dhcp works fine and but altiris does NOT. I would like to experience the dhcp relay agent maybe it will fix my problem (Error e53).
What is the difference between ip helper-address and dhcp relay agent.
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