Concept Guide

• An entry in the DHCP snooping table is not added for a DHCP client interface.
DHCP Server
A switch can operate as a DHCP client and a DHCP server. DHCP client interfaces cannot acquire a dynamic IP address from the DHCP
server running on the switch. Acquire a dynamic IP address from another DHCP server.
Virtual Router Redundancy Protocol (VRRP)
Do not enable the DHCP client on an interface and set the priority to 255 or assign the same DHCP interface IP address to a VRRP virtual
group. Doing so guarantees that this router becomes the VRRP group owner.
To use the router as the VRRP owner, if you enable a DHCP client on an interface that is added to a VRRP group, assign a priority less than
255 but higher than any other priority assigned in the group.
DHCP Relay When DHCP Server and Client are in
Dierent VRFs
When the DHCP server and DHCP clients belong to dierent VRFs on the relay agent, you can congure the system to leak routes across
VRFs.
You can congure the system to leak the following routes across VRFs:
• Connected routes
• The complete routing table
• Selective routes
The following illustration depicts the topology in which routes are leaked between VRFs in the relay agent.
VRF_1 VRF_2
DHCP Server --------------------- DHCP relay agent --------------------------- Client
(10.0.0.1) (10.0.0.2) (20.0.0.2) (20.0.0.4)
Conguring Route Leaking between VRFs on DHCP Relay
Agent
To congure route leaking between VRFs on DHCP relay agent, include the conguration similar to the following along with your DHCP
relay conguration on your system.
Route Leaking for Connected Routes
!
ip vrf VRF_1
ip route-import 1:1 rmap1
ip route-export 2:2 rmap2
!
ip vrf VRF_2
ip route-import 2:2
ip route-export 1:1
!
route-map rmap1 permit 10
match source-protocol connected
!
Dynamic Host
Conguration Protocol (DHCP) 273