interfaces dataplane <interface-name> vrrp vrrp-group <vrrp-group-id> notify bgp
Sets the BGP update notification when the path taken by the outgoing traffic changes.
- interface-name
- The name of a data plane interface. For more information about the supported interface name formats, refer to Data Plane Interface.
- vrrp-group-id
- The ID of a vrrp downlink group instance.
Configuration mode
interfaces {
dataplane interface-name {
vrrp {
vrrp-group vrrp-group-id {
notify {
bgp
}
}
}
}
}In certain topologies that involve VRRP in downlink LANs and eBGP to ISP in uplink LANs, symmetric routing can be achieved by influencing or changing the path taken by incoming traffic according to the path taken by outgoing traffic.
The edge topology described here can have two vRouters that act as VRRP Master and Backup pair for the downlink LAN of the end hosts. Both VRRP Master and Backup pair routers are connected to an ISP gateway router, each through eBGP. This configuration provides two possible outgoing and incoming paths for the traffic.
When VRRP state changes in downlink, that is, when the path taken by the outgoing traffic changes, vRouters send BGP updates to respective eBGP ISP gateway peers. The update notification contains Multi-Exit Discriminator (MED) or prepend-as-path changes according to the configuration to influence the change in BGP best paths for incoming traffic.
The as-path-string that is used on the active path or the path that includes the VRRP elected master is NONE, that is, no AS-path prepended.
This configuration is required to enable the symmetric routing on vRouters in association with either of the following commands:
- set protocols bgp asn neighbor id vrrp-failover vrrp-group vrrp-group-id med med-value
- set protocols bgp asn neighbor id vrrp-failover vrrp-group vrrp-group-id prepend-as as-path-string