Dell BigIron RX Series, Руководство по настройке

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BigIron RX Series Configuration Guide 857
53-1002253-01
Chapter
27
Configuring MBGP
This chapter provides details on how to configure Multi-protocol Border Gateway Protocol (MBGP) .
MBGP is an extension to BGP that allows a router to support separate unicast and multicast
topologies. BGP4 cannot support a multicast network topology that differs from the network’s
unicast topology. MBGP allows you to support a multicast topology that is distinct from the
network’s unicast topology. For example, if you want to dedicate a link on your Internet router to
multicast traffic, use MBGP to handle the routes on that link.
MBGP provides the following benefits:
•
You can support a network whose multicast topology is different from its unicast topology.
Even if the unicast and multicast networks have the same topologies, you can support
different sets of routing policies for unicast and multicast.
•
You can use BGP4's powerful feature set with MBGP.
Figure 116 shows an example of a network that contains both a unicast topology and a multicast
topology. The unicast and multicast router in this example receives unicast and multicast routes
from the Internet. The router advertises the multicast routes to the multicast router and advertises
the unicast routes to the unicast router. Likewise, the unicast and multicast router can advertise
unicast routes received from the unicast router to the Internet, and can advertise multicast routes
received from the multicast router to the Internet.
FIGURE 116 MBGP used when multicast topology is different from unicast topology
An MBGP router learns MBGP routes from its neighbors in other ASs. An MBGP router also can
advertise MBGP routes to its neighbors. The Brocade implementation of MBGP enables you to
advertise multicast routes from the following sources:
•
Explicitly configured network prefixes
•
Static IP multicast routes
•
Directly-connected multicast routes redistributed into MBGP.
You can configure an aggregate address to aggregate network prefixes into a single, more general
prefix for advertisement.
MBGP is described in detail in RFC 2858.
Internet
AS 10
BGP4
MBGP
MBGP
BGP4
Multicast
Router
Unicast
Router
Unicast
and
Multicast
Router