Routing over VLAGs

When a routing protocol such as OSPF is used for peering over a VLAG, the cluster egress filtering rules prevent routed packets from egressing VLAGs, if the packet crosses the cluster links before egressing the VLAG.

There are some sub-optimal network designs, for example when vrouter-interfaces are created on only one side of the cluster due to the use of /30 network addresses, and the cluster active-active routing feature does not help with the implementation. These sub-optimal network designs may cause Layer 3 traffic to route through the cluster even when the point of exit is a VLAG that is locally up on each cluster member.

To help in those cases, a new parameter is provided to allow packets crossing the cluster to egress out of VLAGs, if the packet is routed after crossing the cluster.

To enable this feature, use the following command:




Specify if you want to enable or disable routing to VLAGs from cluster links

CLI (network-admin@vs-spine1) > system-settings-show

switch:             spine1

routing-over-vlags: off

switch:             vanquish2

switch:             vanquish4

routing-over-vlags: off

switch:             vanquish3

routing-over-vlags: off


CLI (network-admin@spine1) > system-settings-modify routing-over-vlags


CLI (network-admin@spine1) > switch-local system-settings-show

switch: spine1

routing-over-vlags: on