Virtual Router Redundancy Protocol (VRRP) support

The Cisco Nexus 3550-T Triton L3 switch supports VRRPv2 without authentication. VRRP works in combination with regular ethernet interfaces and VLAN interfaces.

Configuring VRRP:

Since VRRP uses the IP address of the underlying interface (i.e, the underlying eth, VLAN or port-channel interface) to make priority decision during failover, you must configure the underlying interface on which the VRID is to be executed, with an IP address. Failing to do so will result in the VRID instance failing to run. Your Nexus 3550-T Triton's command line application will warn you about this in the show vrrp output listing.

Viewing all currently configured VRRP VRID instances:

To view all currently configured VRID instances, use the following commands:

admin@sroo3# show vrrp
Iface ethernet10 - vrID 110
  Configured state is DOWN
    !!! Master iface has no ip addr !!!
  Virtual IP address is
  Virtual MAC address is 00:00:5E:00:01:6E
  Advertise time 1000ms
  Skew time 609ms
  Master down (failover) timer 3609 ms
  Configured priority 100

Creating/deleting VRIDs on interfaces:

Creating/deleting a VRID on routed ethernet interfaces:

To create a new VRID on a regular routed ethernet interface, use the following commands:

admin@sroo3# configure
admin@sroo3(config)# int ethernet10
admin@sroo3(config-if-et10)# no switchport
admin@sroo3(config-if-et10)# vrrp 110
admin@sroo3(config-if-et10-vrrp)#

You will now be in the VRRP configuration sub-mode. See the "VRRP Configuration sub-mode commands" section to learn more about the supported commands in this sub-mode.

To delete a VRID from a regular routed ethernet interface, use the following commands:

admin@sroo3# configure
admin@sroo3(config)# int ethernet10
admin@sroo3(config-if-et10)# no vrrp 110

Creating/deleting a VRID on VLAN interfaces:

To create a new VRID on a VLAN interface, use the following commands:

admin@sroo3# configure
admin@sroo3(config)# int vlan3
admin@sroo3(config-if-vl3)# vrrp 30
admin@sroo3(config-if-vl3-vrrp)#

You will now be in the VRRP configuration sub-mode. See the "VRRP Configuration sub-mode commands" section to learn more about the supported commands in this sub-mode.

To delete a VRID from a VLAN ethernet interface, use the following commands:

admin@sroo3# configure
admin@sroo3(config)# int vlan3
admin@sroo3(config-if-vl3)# no vrrp 30
admin@sroo3(config-if-vl3)#

Creating/deleting a VRID on port-channels:

To create a new VRID on a VLAN interface, use the following commands:

admin@sroo3# configure
admin@sroo3(config)# int port-channel 3
admin@sroo3(config-if-po3)# vrrp 120
admin@sroo3(config-if-po3-vrrp)#

You will now be in the VRRP configuration sub-mode. See the "VRRP Configuration sub-mode commands" section to learn more about the supported commands in this sub-mode.

To delete a VRID from a VLAN ethernet interface, use the following commands:

admin@sroo3# configure
admin@sroo3(config)# int port-channel 3
admin@sroo3(config-if-po3)# no vrrp 120
admin@sroo3(config-if-po3)#

VRRP Configuration sub-mode commands:

You may configure the following properties on a VRID instance on the Nexus 3550-T Triton: - IP address. - Operational status (enabled/disabled). - Advertisement interval. - Preemption. - VRouter instance priority.

IP address property:

The IP address of your VRID instance is what the host nodes on your network will use as their gateway address to effectuate redundancy on your network. To set the IP address of your VRID instance, enter VRRP configuration sub-mode and enter the following command:

admin@sroo3(config-if-et10-vrrp)# vrrp-ip-address <A.B.C.D>

You can remove the IP address by negating this command:

admin@sroo3(config-if-et10-vrrp)# no vrrp-ip-address <A.B.C.D>

Operational status property:

You may temporarily enable/disable a VRID for convenience by changing its operational state, using the following commands in VRRP configuration sub-mode:

To disable a VRID:

admin@sroo3(config-if-et10-vrrp)# shutdown

To enable a VRID:

admin@sroo3(config-if-et10-vrrp)# no shutdown

The advertisement interval property determines how often your VRID instance will issue multicast messages to the other redundant routers hosting that VRID number on that subnet in order to detect when the master VRouter has gone down. As a result of that, this property also determines how quickly your VRRP redundancy setup will respond to failover events.

To configure this property, enter the VRRP configuration sub-mode and issue the following commands:

This command configures the advertisement interval in seconds:

admin@sroo3(config-if-et10-vrrp)# timer <1-255>

This command does the same thing, but allows you to specify the interval in milliseconds:

admin@sroo3(config-if-et10-vrrp)# timer msec <20-30000>

Preemption property:

VRRP pre-emption ensures that if the highest priority master goes down, and a lower priority backup router becomes the new master, then whenever the highest priority master returns to full operation, it will pre-empt the lower priority router and assume the master role.

To enable pre-emption:

admin@sroo3(config-if-et10-vrrp)# no preempt disable

To disable pre-emption:

admin@sroo3(config-if-et10-vrrp)# preempt disable

VRouter instance priority property:

This property denotes which VRRP router's VRID instance is the preferred master (default value is 100). To set the priority of a VRID, issue the following commands in VRRP configuration sub-mode:

admin@sroo3(config-if-et10-vrrp)# priority <1-255>