DHCP Relay feature forwards DHCP packets between client and server when the DHCP Server is not in the same broadcast domain as the client. DHCP Relay should be configured on the gateway interface (SVI/ L3 interface ) for the clients.

EOS DHCP relay agent forwards all the DHCP requests from the clients using the primary IP address of the interface as

EOS supports the DHCP Relay feature, which relays DHCP Requests/Responses between DHCP clients and DHCP servers in different subnets. However, the DHCP server does not have visibility of where the request originated from and can only make IP address allocation decisions based on the client MAC address alone (client MAC address is included in the DHCP packet as part of the payload). To remedy that, DHCP Option-82 was formalized to allow relay agents to include Remote ID and Circuit ID so that DHCP servers can apply a more intelligent allocation policy.

DHCP relay agent uses one of the addresses configured on the interface as the source IP when relaying messages to the

DHCP 4.21.0F

IP Locking is an EOS feature configured on an Ethernet Layer 2 port.  When enabled, it ensures that a port will only permit IP and ARP packets with IP source addresses that have been authorized. As of EOS-4.25.0F release update, IP Locking can run in two modes - IPv4 Locking (which will be referred to as IP Locking) and IPv6 Locking, which can be configured using the commands mentioned in the below sections. IP Locking prevents another host on a different interface from claiming ownership of an IP address through either IP or ARP spoofing.

EOS 4.23.0F adds support for redistributing DHCPv6 routes in IS IS when using the multi agent routing protocol mode.