Address Families

The BGP multiprotocol extensions specify that BGP can exchange information within different types of address families. The JUNOSe BGP implementation defines the following different types of address families:

• Unicast IPv4—If you do not explicitly specify the address family, the router is configured to exchange unicast IPv4 addresses by default. You can also configure the router to exchange unicast IPv4 routes in a specified VRF.
• Multicast IPv4—If you specify the multicast IPv4 address family, you can use BGP to exchange routing information about how to reach a multicast source instead of a unicast destination. For information about BGP multicasting commands, see Configuring BGP Routing . For a general description of IPv4 multicasting, see IPv4 Multicast Overview in the JUNOSe Multicast Routing Configuration Guide.
• VPN IPv4—If you specify the VPN-IPv4 (also known as VPNv4) address family, you can configure the router to provide IPv4 VPN services over an MPLS backbone. These VPNs are often referred to as BGP/MPLS VPNs.
• Unicast IPv6—If you specify the IPv6 unicast address family, you can configure the router to exchange unicast IPv6 routes or unicast IPv6 routes in a specified VRF. For a description of IPv6, see IPv6 Overview in the JUNOSe IP, IPv6, and IGP Configuration Guide.
• Multicast IPv6—If you specify the multicast IPv6 address family, you can use BGP to exchange routing information about how to reach an IPv6 multicast source instead of an IPv6 unicast destination. For a general description of IPv6 multicasting, see IPv4 Multicast Overview in the JUNOSe Multicast Routing Configuration Guide.
• VPN IPv6—If you specify the VPN-IPv6 address family, you can configure the router to provide IPv6 VPN services over an MPLS backbone. These VPNs are often referred to as BGP/MPLS VPNs.
• L2VPN—If you specify the L2VPN address family, you can configure the PE router for VPLS L2VPNs or VPWS L2VPNs to exchange layer 2 network layer reachability information (NLRI) for all VPLS or VPWS instances. Optionally, you can use the signaling keyword with the address-family command for the L2VPN address family to specify BGP signaling of L2VPN reachability information. Currently, you can omit the signaling keyword with no adverse effects. For a description of VPLS, see Configuring VPLS. For a description of VPWS, see Configuring VPWS.
• Route-target—If you specify the route-target address family, you can configure the router to exchange route-target membership information to limit the number of routes redistributed among members. For a description of route-target filtering, see Constraining Route Distribution with Route-Target Filtering.
• VPLS—If you specify the VPLS address family, you can configure the router to exchange layer 2 NLRI for a specified VPLS instance. For a description of VPLS, see Configuring VPLS.
• VPWS—If you specify the VPWS address family, you can configure the PE router to exchange layer 2 NLRI for a specified VPWS instance. For a description of VPWS, see Configuring VPWS.

For information about specifying an address family, see Multicast Services over VPNs.

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