3Com Switch 8800 Configuration Guide Chapter 30 MSDP Configuration
30-9

I. Using MSDP outbound filter

MSDP outbound filter of are functional in:
z Filtering off all the (S, G) entries
z Forwarding only the SA messages permitted by the advanced ACL
Please perform the following configurations in MSDP view.
Table 30-10 Using MSDP outbound filter to control the source information forwarded
Operation Command
Filter off all the SA messages to a specified
MSDP peer peer peer-address sa-policy
export
Forward the SA messages permitted by the
advanced ACL to a specified MSDP peer peer peer-address sa-policy
export [ acl acl-number ]
Remove the filtering over the source
information forwarded undo peer peer-address
sa-policy export

II. Using TTL to filter SA messages with encapsulated data

An SA message with encapsulated data can reach the specified MSDP peer only when
the TTL in its IP header is no less than the threshold. Therefore, the forwarding of SA
messages with encapsulated data can be controlled by configuring the TTL threshold.
For example, you can set the TTL theshold for intra-domain multicast traffic as 10 if you
wish to restrict SA messages with TTL less than or equal to 10 carrying encapsulated
data from being propagated. If you set the TTL threshold greater than 10, then they can
be propagated to outside.
Please perform the following configurations in MSDP view.
Table 30-11 Using TTL to filter SA messages with encapsulated data
Operation Command
Filter off the multicast data encapsulated in
the first SA message aiming at a specified
MSDP peer peer peer-address minimum-ttl ttl
Remove the TTL threshold configuration undo peer peer-address
minimum-ttl
The default value of TTL threshold is 0.
30.2.10 Controlling the Received Source Information
Please perform the following configurations in MSDP view.