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Cisco Viptela SDWAN : VRRP protocol

August 27, 2021 ,

Today we are going to talk about VRRP configuration on the Cisco Viptela. Most of you know about VRRP protocol. Virtual Router Redundancy Protocol (VRRP), which allows multiple routers to share a common virtual IP address for default gateway redundancy, select the VRRP tab. 

VRRP is very similar to HSRP; if you understood HSRP you’ll have no trouble with VRRP which is a standard protocol defined by the IETF in RFC 3768

VRRP definition

  • Protocol : IETF – RFC 3768
  • Number of groups: 255 groups maximum
  • Active/Standby: 1 active and several backups.
  • Virtual IP Address: Can be the same as the real IP address on an interface.
  • Multicast address: 224.0.0.18
  • Tracking: Objects
  • Timers: Hello timer 1 second, hold time 3 seconds.

Here in this article we will talk about the VRRP protocol used in the Cisco Viptela SDWAN. We have multiple parameters used in the VRRP protocol.

Fig 1.1- Cisco Viptela VRRP

Parameters

  • Virtual Router ID: Enter the virtual router ID, which is a numeric identifier of the virtual router. The value is 1-255
  • Priority: There router with the highest priority is elected as primary. If two vEdge routers have the same priority, the one with the higher IP address is elected as primary. The value is 1-254, the default value is 100.
  • Timer : Specify how often the VRRP primary sends VRRP advertisement messages. If subordinate routers miss three consecutive VRRP advertisements, they elect a new primary. Range: 1 through 3600 seconds, Default: 1 second
  • Track OMP: Click On for VRRP to track the Overlay Management Protocol (OMP) session running on the WAN connection. If the primary VRRP router loses all its OMP sessions, VRRP elects a new default gateway from those that have at least one active OMP session.
  • Track Prefix List: Track both the OMP session and a list of remote prefixes, which is defined in a prefix list configured on the local router. If the primary VRRP router loses all its OMP sessions, VRRP failover occurs as described for the Track OMP option. In addition, if reachability to one of the prefixes in the list is lost, VRRP failover occurs immediately, without waiting for the OMP hold timer to expire, thus minimizing the amount of overlay traffic is dropped while the vEdge routers determine the VRRP primary.
  • IP Address: This address must be different from the configured interface IP addresses of both the local vEdge router and the peer running VRRP.

By default, VRRP uses of the state of the service (LAN) interface on which it is running to determine which vEdge router is the primary virtual router. if a vEdge router loses all its WAN control connections, the LAN interface still indicates that it is up even though the router is functionally unable to participate in VRRP.

Configurations

Configure VRRP Interface:
NDNA_vEdge(config-vpn)# interface ge0/0/1
NDNA_vEdge(config-interface-ge)# ip address 172.16.2.3/24
NDNA_vEdge(config-interface-ge)# vrrp 2

Configure Ip address for Virtual router ID
NDNA_vEdge(config-vrrp)# ip address 172.16.2.1

Other Parameters configuration
NDNA_vEdge(config-vrrp)# priority 100
NDNA_vEdge(config-vrrp)# timer 3
NDNA_vEdge(config-vrrp)# track-omp
NDNA_vEdge(config-vrrp)# track-prefix-list NDNA-prefix

Output