3Com 8807 Configuration Manual page 480

480 C 45: MSDP C
HAPTER
Controlling the Source
Information Forwarded
ONFIGURATION
Multicast group addresses are described in ACL. If no ACL is specified, all SA
request messages sent by the corresponding MSDP peer will be ignored. If an ACL
is specified, only SA request messages of the groups permitted by the ACL will be
processed.
Controlling of source information also includes that of forwarding and receiving
source information besides that of creating source information. The outbound
filter or time to live (TTL) threshold of SA messages can be used to control the SA
message forwarding. By default, all SA messages are forwarded to other MSDP
peers.
Using MSDP outbound filter
MSDP outbound filter of are functional in:
Filtering off all the (S, G) entries
■
Forwarding only the SA messages permitted by the advanced ACL
■
Please perform the following configurations in MSDP view.
Table 474 Use MSDP outbound filter to control the source information forwarded
Operation
Filter off all the SA messages to a specified
MSDP peer
Forward the SA messages permitted by the
advanced ACL to a specified MSDP peer
Remove the filtering over the source
information forwarded
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 threshold 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 475 Use TTL to filter SA messages with encapsulated data
Operation
Filter off the multicast data encapsulated in
the first SA message aiming at a specified
MSDP peer
Remove the TTL threshold configuration
The default value of TTL threshold is 0.
Command
peer peer-address sa-policy export
peer peer-address sa-policy export acl
acl-number
undo peer peer-address sa-policy export
Command
peer peer-address minimum-ttl ttl
undo peer peer-address minimum-ttl