Concept Guide
MBGP uses either an IPv4 address congured on the interface (which is used to establish the IPv6 session) or a stable IPv4 address that is
available in the box as the next-hop address. As a result, while advertising an IPv6 network, exchange of IPv4 routes does not lead to
martian next-hop message logs.
NOTE: It is possible to congure BGP peers that exchange both unicast and multicast network layer reachability information
(NLRI), but you cannot connect multiprotocol BGP with BGP. Therefore, you cannot redistribute multiprotocol BGP routes into
BGP.
MBGP for IPv4 Multicast
PIM feature uses IPv4 multicast routing for data distribution. MBGP provides a link that is dedicated specic to multicast trac. MBGP
also allows a unicast routing apart from the multicast routing. A multicast routing protocol, such as PIM, uses both the unicast and
multicast BGP database to form a routing table for unicast and multicast. You can congure BGP peers that exchange both unicast and
multicast Network Layer Reachability Information (NLRI) in which MBGP routes is redistributed into BGP. The default is IPv4 unicast.
BGP Address Family model
Dell EMC Networking OS supports BGP address family identier (AFI) with MBGP to provide scalability for multiple AFI and subsequent
address family identier (SAFI) congurations. MBGP carries routing information for address families (IPv4 and IPv6) of multiple network-
layer protocols. Each address family has a separated BGP database, so that you can congure BGP policy based on address family.
IPv4 and IPv6 address family
The IPv4 address family conguration in Dell EMC Networking OS is used for identifying routing sessions for protocols that use IPv4
address. You can specify multicast within the IPv4 address family. The default of address family conguration is IPv4 unicast. You can
congure the VRF instances for IPv4 address family conguration.
The IPv6 address family conguration is used for identifying routing sessions for protocols that use IPv6 address. You can specify unicast
within the IPv6 address family. You can congure the VRF instances for IPv6 address family conguration.
Implement BGP with Dell EMC Networking OS
The following sections describe how to implement BGP on Dell EMC Networking OS.
Additional Path (Add-Path) Support
The add-path feature reduces convergence times by advertising multiple paths to its peers for the same address prex without replacing
existing paths with new ones. By default, a BGP speaker advertises only the best path to its peers for a given address prex. If the best
path becomes unavailable, the BGP speaker withdraws its path from its local RIB and recalculates a new best path. This situation requires
both IGP and BGP convergence and can be a lengthy process. BGP add-path also helps switchover to the next new best path when the
current best path is unavailable.
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Border Gateway Protocol version 4 (BGPv4)