3Com Switch 8800 Configuration Guide Chapter 21 BGP Configuration21-4z MP_REACH_NLRI: Multiprotocol Reachable NLRI, used to advertise reachableroutes and the next hop information.z MP_UNREACH_NLRI: Multiprotocol Unreachable NLRI, used to deleteunreachable routes.These two attributes are optional non-transitive. Therefore, the BGP speaker that doesnot provide multiple protocols ability will ignore the information of them nor transferthem to other peers.III. Address familyThe network layer protocols are differentiated by address families in BGP. SeeRFC1700 (assigned numbers) for the possible values of these address families. TheSwitch 8800 provides various MBGP extended applications, including extension ofmulticast, VPN, and so on. Different extended applications should be configured in theirown address family views.For more information about the commands executed in MBGP address family view, see“Multicast Protocol” and “MPLS Configuration” of this manual.21.1.5 BGP Peer and Peer GroupI. Definition of peer and peer groupA BGP speaker calls peers other BGP speakers which exchange information with it andmultiple related peers compose a peer group.II. Relationship between peer configuration and peer group configurationIn the Switch 8800, a BGP peer must belong to a peer group. If you want to configure aBGP peer, you need first to create a peer group and then add a peer into the group.BGP peer group feature can simplify user configuration and improve routeadvertisement efficiency. When added into a peer group, a peer inherits all theconfiguration of the group.If the configuration of a peer group changes, the configuration of its member peers alsoalters. Some attributes can be configured to a particular member peer by specifying itsIP address. The attributes configured in this way is with higher priority than those byconfiguring for peer group. It should be noted that all member peers must use the sameupdate policy as its group, but may use different ingress policy.21.2 Configuring BGPThese categories are involved in BGP configuration:1) Basic BGP configurationz Enabling BGPz Configuring Basic Features for BGP Peer2) BGP peer configuration
