VRF and Static Route Next Hop Lookup (S-, K-Series)

When a subnet is reachable from a VRF different from the ingress VRF, a static route can be configured specifying that the egress VRF instance performs the next hop lookup.

Use the ip route {prefix mask | prefix/prefix-length} vrf egress-vrf command to configure an egress VRF to perform the static route next hop lookup.

Note

The default VRF router is referred to as the global router. Named VRF routers within a device configured using the set router vrf create command are referred to as non-global VRF routers. Static routes are supported between both the global router and any non-global VRF router and between any two non-global VRF routers.

Refer to VRF Overview for the following discussion. Only VRF Internet-Access contains next hop information for destination addresses reachable by the Internet gateway router. If a packet ingresses on VLAN 10 for IP address 192.168.10.5, with a destination address of 66.249.81.104 that is only reachable by the Internet gateway router, a lookup on the VRF Alpha-Group route table will fail. By configuring a static route on VRF Alpha-Group pointing to VRF Internet-Access as the egress VRF, the Internet-Access VRF will be used for the next hop lookup destination address 66.249.81.104.

Note

Using the vrf vrf-name parameter is more dynamic than configuring a standard static route, in that it determines the next hop based upon a route table lookup. A standard static route specifies a single next hop. Should that next hop be unavailable, the subnet is no longer reachable. A standard static route can be configured to reach the next hop that is a member of a different VRF using the syntax: ip route destination-prefix/length next-hop-address interface next-hop-interface. Because the vrf vrf-name parameter provides greater flexibility in determining the next hop, it is recommended that you use the vrf vrf-name parameter.

This example shows how to specify on VRF Alpha-Group that the next hop lookup to destination prefix 66.249.81.0/24, for packets ingressing on VRF Alpha-Group, is performed on VRF Internet-Access:

System(rw-*ha-Group-config)->ip route 66.249.81.0/24 vrf Internet-Access

This example shows how to specify on VRF Alpha-Group that the next hop lookup to destination address 2001:11ac:fd34::/48, for packets ingressing on VRF Alpha-Group, is performed on VRF Internet-Access:

System(rw-*ha-Group-config)->ipv6 route 2001:11ac:fd34::/48 vrf Internet-Access