Inter-VRF route leaking and DHCP relay

In a DHCP relay setting, route leaking is controlled through a single DHCP server (which may be on a different VRF); this permits multiple VRFs to communicate with that server, something that would normally not be permitted. DHCP relay deployments in a data center can use Inter-VRF route leaking to achieve server consolidation; this permits clients in multiple VRFs to communicate with a single DHCP server in a different VRF (normally this is not permitted, as VRFs provide route/traffic isolation).

About this task

The illustration below shows four VRFs, with three of them connecting to the fourth for DHCP services. (For more information on working with DHCP IP Relay, refer to the "DHCPv4" chapter.)

Inter-VRF route leaking example for connecting clients to a DHCP server in a different VRF.

The following example shows setting up Inter-VRF route leaking and DHCP between the red VRF and the blue VRF.

Note

Inter-VRF route leaking supports both IPv4 and IPv6. Use the ip address and ip route commands for IPv4 and the ipv6 address and ipv6 route commands for IPv6. These commands support IP addresses, Ethernet interfaces, and virtual Ethernet (VE) interfaces for the leak destination. Refer to the Extreme SLX-OS Command Reference.

1. Configure VRF forwarding on a VE interface.
   

   device(config)# interface ve 100
   device(config-if-Ve-100)# no shutdown
   device(config-if-Ve-100)# vrf forwarding red     
        <- interface is in VRF "red" ->
   device(config-if-Ve-100)# ip address 10.1.1.1/24
   device(config-if--Ve-100)# ip dhcp relay address 20.1.1.2 use-vrf blue
        <- server is in VRF "blue" -> 

2. Configure the leaked route on VRF "red".
   

   device(config)# vrf red
   device(conf-vrf-red)# address-family ipv4 unicast
   device(vrf-red-ipv4-unicast)# max-route
   device(vrf-red-ipv4-unicast)# ip route 20.1.1.2/32 next-hop-vrf blue 20.2.1.2