address-family
To enter the address family submode for configuring routing protocols such as Border Gateway Protocol (BGP), Routing Information Protocol (RIP), and static routing, use the address-family command in address family configuration submode. To disable the address family submode for configuring routing protocols, use the no form of this command.
VPN-IPv4 Unicast
address-family vpnv4 [unicast]
no address-family vpnv4 [unicast]
IPv4 Unicast
address-family ipv4 [unicast]
no address-family ipv4 [unicast]
IPv4 Unicast with CE router
address-family ipv4 [unicast] vrf vrf-name
no address-family ipv4 [unicast] vrf vrf-name
Syntax Description
vpnv4 |
Configures sessions that carry customer Virtual Private Network (VPN)-IPv4 prefixes, each of which has been made globally unique by adding an 8-byte route distinguisher. |
ipv4 |
Configures sessions that carry standard IPv4 address prefixes. |
unicast |
(Optional) Specifies unicast prefixes. |
vrf vrf-name |
Specifies the name of a VPN routing/forwarding instance (VRF) to associate with submode commands. |
Command Default
Routing information for address family IPv4 is advertised by default when you configure a BGP session using the neighbor remote-as command unless you execute the no bgp default ipv4-activate command.
Command Modes
Address family configuration
Command History
Release |
Modification |
---|---|
12.0(5)T |
This command was introduced. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2SX |
This command is supported in the Cisco IOS Release 12.2SX train. Support in a specific 12.2SX release of this train depends on your feature set, platform, and platform hardware. |
Usage Guidelines
Using the address-family command puts the router in address family configuration submode (prompt: (config-router-af)# ). Within this submode, you can configure address-family specific parameters for routing protocols, such as BGP, that can accommodate multiple Layer 3 address families.
To leave address family configuration submode and return to router configuration mode, enter the exit-address-family or the exit command.
Examples
The address-family command in the following example puts the router into address family configuration submode for the VPNv4 address family. Within the submode, you can configure advertisement of Network Layer Reachability Information (NLRI) for the VPNv4 address family using neighbor activate and other related commands:
router bgp 100
address-family vpnv4
The address-family command in the following example puts the router into address family configuration submode for the IPv4 address family. Use this form of the command, which specifies a VRF, only to configure routing exchanges between provider edge (PE) and customer edge (CE) devices. This address-family command causes subsequent commands entered in the submode to be executed in the context of VRF vrf2. Within the submode, you can use neighbor activate and other related commands to accomplish the following:
-
Configure advertisement of IPv4 NLRI between the PE and CE routers.
-
Configure translation of the IPv4 NLRI (that is, translate IPv4 into VPNv4 for NLRI received from the CE, and translate VPNv4 into IPv4 for NLRI to be sent from the PE to the CE).
-
Enter the routing parameters that apply to this VRF.
The following example shows how to enter the address family submode:
Router(config)# router bgp 100
Router(config-router)# address-family ipv4 unicast vrf vrf2