Concept Guide

GroupAddr SourceAddr RPAddr LearnedFrom Expire UpTime
229.0.50.2 24.0.50.2 200.0.0.50 10.0.50.2 73 00:13:49
229.0.50.3 24.0.50.3 200.0.0.50 10.0.50.2 73 00:13:49
229.0.50.4 24.0.50.4 200.0.0.50 10.0.50.2 73 00:13:49
DellEMC#ip msdp sa-cache rejected-sa
MSDP Rejected SA Cache
3 rejected SAs received, cache-size 32766
UpTime GroupAddr SourceAddr RPAddr LearnedFrom Reason
00:33:18 229.0.50.64 24.0.50.64 200.0.1.50 10.0.50.2 Rpf-Fail
00:33:18 229.0.50.65 24.0.50.65 200.0.1.50 10.0.50.2 Rpf-Fail
00:33:18 229.0.50.66 24.0.50.66 200.0.1.50 10.0.50.2 Rpf-Fail
Limiting the Source-Active Messages from a Peer
To limit the source-active messages from a peer, use the following commands.
1 OPTIONAL: Store sources that are received after the limit is reached in the rejected SA cache.
CONFIGURATION mode
ip msdp cache-rejected-sa
2 Set the upper limit for the number of sources allowed from an MSDP peer.
CONFIGURATION mode
ip msdp peer peer-address sa-limit
The default limit is 100K.
If the total number of sources received from the peer is already larger than the limit when this conguration is applied, those sources are
not discarded. To enforce the limit in such a situation, rst clear the SA cache.
Preventing MSDP from Caching a Local Source
You can prevent MSDP from caching an active source based on source and/or group. Because the source is not cached, it is not
advertised to remote RPs.
1 OPTIONAL: Cache sources that are denied by the redistribute list in the rejected SA cache.
CONFIGURATION mode
ip msdp cache-rejected-sa
2 Prevent the system from caching local SA entries based on source and group using an extended ACL.
CONFIGURATION mode
ip msdp redistribute list
Example of Verifying the System is not Caching Local Sources
When you apply this lter, the SA cache is not aected immediately. When sources that are denied by the ACL time out, they are not
refreshed. Until they time out, they continue to reside in the cache. To apply the redistribute lter to entries already present in the SA
cache, rst clear the SA cache. You may optionally store denied sources in the rejected SA cache.
R1(conf)#do show run msdp
!
ip multicast-msdp
ip msdp peer 192.168.0.3 connect-source Loopback 0
ip msdp redistribute list mylocalfilter
ip msdp cache-rejected-sa 1000
R1_E600(conf)#do show run acl
!
ip access-list extended mylocalfilter
seq 5 deny ip host 239.0.0.1 host 10.11.4.2
seq 10 deny ip any any
Multicast Source Discovery Protocol (MSDP)
515