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Set a Clause with a Continue Clause
If the route-map entry contains sets with the continue clause, the set actions operation is performed first then the continue
clause jump to the specified route map entry.
● If a set actions operation occurs in the first route map entry and then the same set action occurs with a different value in a
subsequent route map entry, the last set of actions overrides the previous set of actions with the same set command.
● If the set community additive and set as-path prepend commands are configured, the communities and AS
numbers are prepended.
Enabling MBGP Configurations
Multiprotocol BGP (MBGP) is an enhanced BGP that carries IP multicast routes. BGP carries two sets of routes: one set
for unicast routing and one set for multicast routing. The routes associated with multicast routing are used by the protocol
independent multicast (PIM) to build data distribution trees.
The S5000 supports MBGP for IPv6 Unicast and IPv4 multicast.
Dell Networking OS MBGP is implemented per RFC 1858. You can enable the MBGP feature per router and/or per peer/
peer-group.
The default is IPv4 Unicast routes.
When you configure a peer to support IPv4 multicast, Dell Networking OS takes the following actions:
● 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 by using 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MP_UNREACH_NLRI, for feasible and withdrawn routes, respectively.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 Dell Networking OS 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.
Border Gateway Protocol IPv4 (BGPv4)
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