Enabling IPv4 VRRPv3

VRRPv3 supports IPv4 sessions as well as IPv6 sessions. To configure a VRRPv3 session for IPv4 assign a virtual router group with the v3 option to the device. The device must be a router or another device that supports Layer 3 routing.

Perform this task on all devices that are to run IPv4 VRRPv3. The device to which the virtual IP address belongs determines the initial master device status with all the other devices acting as backups.

Enter the configure terminal command to access global configuration mode.
```
device# configure terminal
```
To globally enable VRRP, enter the protocol vrrp command.
```
device(config)# protocol vrrp
```
Configure the Ethernet interface.
```
device(config)# interface ethernet 1/6 
```
In this example, Ethernet interface configuration mode is entered and the interface is assigned with a slot/port number of 1/6.
Enter an IPv4 address for the interface using the ip address command.
```
device(conf-if-eth-1/6)# ip address 192.168.5.2/24
```
Enter the vrrp-group command with a number to assign a virtual router group to the device and a version to configure VRRPv3.
```
device(conf-if-eth-1/6)# vrrp-group 10 version 3
```
In this example, a VRRPv3 group is assigned and VRRP group configuration mode is entered.
Enter the advertisement-interval command with a number in milliseconds to configure the interval at which the master VRRP router advertises its existence to the backup routers.
```
device(config-vrrp-group-10)# advertisement-interval 2000
```
In this example, the interval is expressed as 2000 milliseconds because VRRPv3 uses milliseconds instead of seconds for the advertisement interval.
Enter the virtual-ip command to assign a virtual IP address to a VRRPv3 group.
```
device(config-vrrp-group-10)# virtual-ip 192.168.5.2
```
In this example, the IPv4 address of the virtual router is assigned to VRRPv3 group 10. This virtual IP address belongs to this device and this device will assume the role of the master device.

The following example shows how to enable an IPv4 VRRPv3 session by assigning virtual IP addresses to a VRRPv3 virtual group.

device# configure
device(config)# protocol vrrp
device(config)# interface ethernet 1/6 
device(config-if-eth-1/6)# ip address 192.168.5.2/24
device(config-if-eth-1/6)# vrrp-group 10 version 3
device(config-vrrp-group-10)# advertisement-interval 2000
device(config-vrrp-group-10)# virtual-ip 192.168.5.2