Brocade TurboIron 24X Series Configuration Guide - Manual (Page 872)

838 Brocade TurboIron 24X Series Configuration Guide
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Multicast Source Discovery Protocol (MSDP)
MSDP mesh groups
A PIM Sparse domain can have several RPs that are connected to each other to form an MSDP
mesh group. To qualify as a mesh group, the RPs have to be fully meshed; that is, each RP must be
connected to all peer RPs in a domain. (See Figure 109.)
A mesh group reduces the forwarding of SA messages within a domain. Instead of having every RP
in a domain forward SA messages to all the RPs within that domain, only one RP forwards the SA
message. Since an MSDP mesh group is fully meshed, peers do not forward SA messages received
in a domain from one member to every member of the group. The RP that originated the SA or the
first RP in a domain that receives the SA message is the only one that can forward the message to
the members of a mesh group. An RP can forward an SA message to any MSRP router as long as
that peer is farther away from the originating RP than the current MSRP router.
Figure 109 shows an example of an MSDP mesh group. In a PIM-SM mesh group the RPs are
configured to be peers of each other. They can also be peers of RPs in other domains.
Configuring an MSDP mesh group
To configure an MSDP mesh group, enter commands such as the following on each device that will
be included in the mesh group:
TurboIron(config)#router msdp
TurboIron(config-msdp-router)#msdp-peer 10.1.3.1 connect-source loopback 1
TurboIron(config-msdp-router)#msdp-peer 10.1.4.1 connect-source loopback 1
TurboIron(config-msdp-router)#msdp-peer 10.1.2.1 connect-source loopback 1
TurboIron(config-msdp-router)#msdp-peer 10.17.17.7
TurboIron(config-msdp-router)#mesh-group 1234 10.1.4.1
TurboIron(config-msdp-router)#mesh-group 1234 10.1.3.1
TurboIron(config-msdp-router)#mesh-group 1234 10.1.2.1
TurboIron(config-msdp-router)#exit
Syntax: [no] mesh-group <group-name> <peer-address>
The example configuration above reflects the configuration in Figure 109. On RP 10.1.1.1, you
specify its peers within the same domain (10.1.3.1, 10.1.4.1, and 10.1.2.1).
You first configure the MSDP peers using the msdp-peer command to assign their IP addresses
and the loopback interfaces. This information will be used as the source for sessions with the
neighbor.
Next, place the MSDP peers within a domain into a mesh group. Use the mesh-group command.
There are no default mesh groups.
The <group-name> parameter identifies the group. Enter up to 31 characters for group-name. You
can have up to 4 mesh groups within a multicast network. Each mesh group can include up to 32
peers.
The <peer-address> parameter specifies the IP address of the MSDP peer that is being placed in
the group.
NOTE
On each of the device that will be part of the mesh-group, there must be a mesh-group definition for
all the peers in the mesh-group.
Up to 32 MSDP peers can be configured per mesh group.