Multiprotocol Extensions for BGP (MBGP or MP-BGP), sometimes referred to as Multiprotocol BGP or Multicast BGP and defined in

IETF The Internet Engineering Task Force (IETF) is a standards organization for the Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster or requirements and a ...

RFC 4760, is an extension to

Border Gateway Protocol Border Gateway Protocol (BGP) is a standardized exterior gateway protocol designed to exchange routing and reachability information among autonomous systems (AS) on the Internet. BGP is classified as a path-vector routing protocol, and it makes ...

(BGP) that allows different types of addresses (known as address families) to be distributed in parallel. Whereas standard BGP supports only IPv4

unicast Unicast is data transmission from a single sender (red) to a single receiver (green). Other devices on the network (yellow) do not participate in the communication. In computer networking, unicast is a one-to-one transmission from one point in ...

addresses, Multiprotocol BGP supports

IPv4 Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP). It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. IPv4 was the first version de ...

and

IPv6 address An Internet Protocol Version 6 address (IPv6 address) is a numeric label that is used to identify and locate a network interface of a computer or a network node participating in a computer network using IPv6. IP addresses are included in the pac ...

es and it supports unicast and multicast variants of each. Multiprotocol BGP allows information about the topology of

IP multicast IP multicast is a method of sending Internet Protocol (IP) datagrams to a group of interested receivers in a single transmission. It is the IP-specific form of multicast and is used for streaming media and other network applications. It uses speci ...

-capable routers to be exchanged separately from the topology of normal

unicast routers. Thus, it allows a multicast routing topology different from the unicast routing topology. Although MBGP enables the exchange of inter-domain multicast routing information, other protocols such as the

Protocol Independent Multicast 400px, Example of a multicast network architecture Protocol-Independent Multicast (PIM) is a family of multicast routing protocols for Internet Protocol (IP) networks that provide one-to-many and many-to-many distribution of data over a LAN, ...

family are needed to build trees and forward multicast traffic. As an enhancement of BGP-4, MP-BGP provides routing information for various protocols, such as IPv6 (BGP4+) and multicast: * MP-BGP maintains unicast and

multicast routing Multicast routing is one of the routing protocols in IP networking. CISCO Security Research & Operations- 3 June 201Understanding Unicast Reverse Path Forwarding , Cisco -unicast-reverse-path-forwarding/ref> There are several multicast rout ...

information, and stores both types in different routing tables to ensure their separation. * MP-BGP supports unicast and multicast, and constructs different network topologies for each. * MP-BGP can maintain unicast and multicast routes based on routing policies. The unicast routing policies and configurations supported by BGP-4 can mostly be applied to multicast. Multiprotocol BGP is also widely deployed in case of MPLS L3 VPN, to exchange VPN labels learned for the routes from the customer sites over the MPLS network, in order to distinguish between different customer sites when the traffic from the other customer sites comes to the

provider edge router A provider edge router (PE router) is a router between one network service provider's area and areas administered by other network providers. A network provider is usually an Internet service provider as well (or only that). The term ''PE router ...

(PE router) for routing.

References

Routing {{Computer-stub