address-family ipv4

[James Hoggard]

Hi,

I want to understand VPNV4 and IPV4 address family.

when looking our PE router under the VPNV4 address family we have 4 commands

address-family vpnv4
 neighbor partial-table send-community both
 neighbor 1.1.1.1 activate
 neighbor 2.2.2.2 activate
 neighbor 3.3.3.3 activate 

The address’s above are our route reflectors obviously on different ip’s

Do you need this command to bring up the IPV4 address family? so the first thing to do is create your address-family vpnv4 then your IPV4 address family?

[medhat elsaeed]

Hello,

address-family ipv4

is for the global routing table

address-family vpnv4

for the VRF  routing (VPNV4)

Regards.

[pabloboscariol]

James, 

in IOS (not on XR!!), you will create the neighbor under the BGP process. If you don't set the "no bgp default ipv4-unicast", all the neighbors are going to have the ipv4 AFI activated as default.

When you issue (under router bgp xxx) the command "address-family vpnv4", first, you're enabling the vpnv4 AFI in the local bgp process. If inside that AFI, you issue "neighbor 1.1.1.1 activate", you're enabling vpnv4 AFI for that neighbor too! so the neighbor is going to be reset, and it will negotiate the AFI.

I hope to help you. have a great day!

Pablo 

[ajay chauhan]

Hi James,

There are multiple options available when you configure BGP on cisco routers.

(config-router)#address-family ?
  ipv4   Address family
  ipv6   Address family
  nsap   Address family
  vpnv4  Address family

More options on new codes---
 

IPV4 is for V4 address,IPv6 for V6 address and VPN4 is to carry VPN routes when using MPLS. This is basically gives you more options to manage bgp configuration. By default all the neighbors under address family are disabled hence activate command is required.

You can define yours neighbors under normal BGP process with no bgp default ipv4-unicast which will disable default behavior of IOS to exchange IPV4 routes and later on you can activate that neighbor in address family you want to use for route exchange.

Thanks

Ajay