Activate IPv6 Address Family for a BGP Neighbor Using User Defined VRF

To configure multi-protocol BGP for exchanging IPv6 prefixes over IPv4 BGP Sessions for a BGP neighbor using an user defined VRF, do the following:

Access global configuration mode.
```
 device# configure terminal 
```
Access BGP configuration mode.
```
device(config)# router bgp
```
Specify the autonomous system in which your device resides.
```
device(config-bgp-router)# local-as 1000
```

Navigate to the IPv4 Unicast Address Family context of the user defined VRF.

device(config-bgp-router)# address-family ipv4 unicast vrf red
device(config-bgp-ipv4u-vrf)#

Specify the autonomous system in which the remote neighbor resides. Assign the remote AS to the neighbor.
```
device(config-bgp-ipv4u-vrf)# neighbor 192.0.2.10 remote-as 1001
```

Exit out of the IPv4 Address Family context.

device(config-bgp-ipv4u-vrf)# exit
device(config-bgp-router)#

Configure the IPv6 address family.

device(config-bgp-router)# address-family ipv6 unicast vrf red
device(config-bgp-ipv6u-vrf)#

Activate the IPv6 Address Family for the BGP neighbor.

device(config-bgp-ipv6u-vrf)# neighbor 192.0.2.10 activate

The following is a consolidation of tasks to perform to activate IPv6 address family for a BGP peer using user defined VRF.

router bgp
local-as 1000
address-family ipv4 unicast vrf red
neighbor 192.0.2.10 remote-as 1001 
address-family ipv6 unicast vrf red 
neighbor 192.0.2.10 activate