3Com Switch 8800 Advanced Software V5 Configuration Guide

622 CHAPTER 43: MSDP CONFIGURATION
Configuring SA Message
Cache
To reduce the time spent in obtaining the multicast source information, you can
have SA messaged cached on the device. However, the more SA messages are
cached, the larger memory space of the device is used.
With the SA cache mechanism enabled, when receiving a new Join message, the
device will not send an SA request message to its MSDP peer; instead, it acts as
follows:
■ If there is no SA message in the cache, the device will wait for the SA message
sent by its MSDP peer in the next cycle;
■ If there is an SA message in the cache, the device will obtain the information of
all active sources directly from the SA message and join the corresponding SPT.
To protect the device against denial of service (DoS) attacks, you can configure the
maximum number of SA messages the device can cache.
Follow these steps to configure the SA message cache:
Displaying and
Maintaining MSDP
Configure a filtering rule for
receiving or forwarding SA
messages
peer peer-address sa-policy {
import | export } [ acl
acl-number ]
Required
No filtering rule by default
Configure the minimum TTL
value of multicast packets to
be encapsulated in SA
messages
peer peer-address
minimum-ttl ttl-value
Optional
0 by default
To do... Use the command... Remarks
To do... Use the command... Remarks
Enter system view system-view -
Enter MSDP view msdp -
Enable the SA message cache
mechanism
cache-sa-enable Required
Enabled by default
Configure the maximum
number of SA messages the
router can cache
peer peer-address
sa-cache-maximum sa-limit
Required
8192 by default
To do... Use the command... Remarks
View the brief information of
MSDP peers status
display msdp brief Available in any view
View the detailed information
about the status of MSDP
peers
display msdp peer-status [
peer-address ]
Available in any view
View the (S, G) entry
information in the MSDP
cache
display msdp sa-cache [
group-address |
source-address | as-number ]
*
Available in any view
View the number of SA
messages in the MSDP cache
display msdp sa-count [
as-number ]
Available in any view
Reset the TCP connection
with an MSDP peer
reset msdp peer [
peer-address ]
Available in user view