Administrator Guide

● Send a capacity advertisement to the peer in the BGP Open message specifying IPv4 multicast as a supported AFI/SAFI
(Subsequent Address Family Identifier).
● If the corresponding capability is received in the peer’s Open message, BGP marks the peer as supporting the AFI/SAFI.
● When exchanging updates with the peer, BGP sends and receives IPv4 multicast routes if the peer is marked as supporting
that AFI/SAFI.
● Exchange of IPv4 multicast route information occurs through the use of two new attributes called MP_REACH_NLRI and
MP_UNREACH_NLRI, for feasible and withdrawn routes, respectively.
● If the peer has not been activated in any AFI/SAFI, the peer remains in Idle state.
Most BGP IPv4 unicast commands are extended to support the IPv4 multicast RIB using extra options to the command. For a
detailed description of the MBGP commands, refer to the Dell Networking OS Command Line Interface Reference Guide.
● Enables support for the IPv4 multicast family on the BGP node.
CONFIG-ROUTER-BGP mode
address family ipv4 multicast
● Enable IPv4 multicast support on a BGP neighbor/peer group.
CONFIG-ROUTER-BGP-AF (Address Family) mode
neighbor [ip-address | peer-group-name] activate
Configure IPv6 NH Automatically for IPv6 Prefix Advertised over
IPv4 Neighbor
You can configure the system to pick the next hop IPv6 address dynamically for IPv6 prefix advertised over an IPv4 neighbor. If
there is no IPv6 address configured on the local interface, the system uses the IPv4 mapped IPv6 address. If there are multiple
IPv6 addresses configured on the interface, the system uses the lowest IPv6 address configured on that interface. If the
configuration is already present and a new IPv6 address, which is lower than the lowest existing address, is assigned to one of
the peer interfaces, that address is not used as the NH until you flap the interface manually.
To enable BGP to pick the next hop IPv6 address automatically for IPv6 prefix advertised over an IPv4 neighbor, follow this
procedure:
● Enable the system to pick the next hop IPv6 address dynamically for IPv6 prefix advertised over an IPv4 neighbor.
ROUTER-BGP mode mode
neighbor {neighbor-ipv6–address | peer-group name} auto-local-address
Enter either the neighbor IPv6 address or the name of the peer group.
BGP Regular Expression Optimization
The system optimizes processing time when using regular expressions by caching and re-using regular expression evaluated
results, at the expense of some memory in RP1 processor.
BGP policies that contain regular expressions to match against as-paths and communities might take a lot of CPU processing
time, thus affect BGP routing convergence. Also, show bgp commands that get filtered through regular expressions can to
take a lot of CPU cycles, especially when the database is large.
This feature is turned on by default. If necessary, use the bgp regex-eval-optz-disable command in CONFIGURATION
ROUTER BGP mode to disable it.
Debugging BGP
To enable BGP debugging, use any of the following commands.
● View all information about BGP, including BGP events, keepalives, notifications, and updates.
EXEC Privilege mode
debug ip bgp [ip-address | peer-group peer-group-name] [in | out]
● View information about BGP route being dampened.
EXEC Privilege mode
Border Gateway Protocol IPv4 (BGPv4)
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