The DHCP relay feature, forwards DHCP packets between a client and the DHCP server when the server is not in the same broadcast domain as the client. The 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 or on a VLAN. When enabled, it ensures that a configured port or all member ports of a configured VLAN will only permit IP and ARP packets with IP source addresses that have been authorized. IP Locking prevents another host on a different IP Locking enabled interface from claiming ownership of an IP address through either IP or ARP spoofing. Additionally, IP Locking prevents hosts from masquerading as a DHCP server by blocking DHCP (server-to-client) packets.

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