Cisco IE 4000, Software Configuration Manual

Page: 753 / 1066

749
Configuring MSDP
Configuring MSDP
DETAILED STEPS
To return to the default setting (active sources in the dense-mode region do not participate in MSDP), use the no ip msdp
border sa-address interface-id global configuration command.
EXAMPLE
In the following example, the local router is not an RP. It borders a PIM sparse mode region with a dense mode region.
It uses the IP address of Ethernet interface 0 as the “RP” address in SA messages.
Switch(config)# ip msdp border sa-address ethernet0
Configuring an Originating Address other than the RP Address
You can allow an MSDP speaker that originates an SA message to use the IP address of the interface as the RP address
in the SA message by changing the Originator ID. You might change the Originator ID in one of these cases:

If you configure a logical RP on multiple switches in an MSDP mesh group.

If you have a switch that borders a PIM sparse-mode domain and a dense-mode domain. If a switch borders a
dense-mode domain for a site, and sparse-mode is being used externally, you might want dense-mode sources to
be known to the outside world. Because this switch is not an RP, it would not have an RP address to use in an SA
message. Therefore, this command provides the RP address by specifying the address of the interface.
This procedure is optional.
BEFORE YOU BEGIN
If both the ip msdp border sa-address and the ip msdp originator-id global configuration commands are configured,
the address derived from the ip msdp originator-id command specifies the address of the RP.
Table 0-10
Command Purpose
1. configure terminal Enter global configuration mode.
2. ip msdp border sa-address
interface-id
Configure the switch on the border between a dense-mode
and sparse-mode region to send SA messages about active
sources in the dense-mode region.
For interface-id , specify the interface from which the IP
address is derived and used as the RP address in SA
messages.
The IP address of the interface is used as the Originator-ID,
which is the RP field in the SA message.
3. ip msdp redistribute [ list
access-list-name ] [ asn
aspath-access-list-number ]
[ route-map map ]
Configure which (S,G) entries from the multicast routing table
are advertised in SA messages.
For more information, see Redistributing Sources, page 738 .
4. end Return to privileged EXEC mode.
5. show running-config Verify your entries.
6. copy running-config
startup-config (Optional) Save your entries in the configuration file.