Administrator Guide

R1_E600(conf)#do show ip msdp sa-cache
R1_E600(conf)#do show ip msdp sa-cache rejected-sa
MSDP Rejected SA Cache
1 rejected SAs received, cache-size 1000
UpTime GroupAddr SourceAddr RPAddr LearnedFrom Reason
00:02:20 239.0.0.1 10.11.4.2 192.168.0.1 local Redistribute
Preventing MSDP from Caching a Remote Source
To prevent MSDP from caching a remote source, use the following commands.
1 OPTIONAL: Cache sources that the SA filter denies in the rejected SA cache.
CONFIGURATION mode
ip msdp cache-rejected-sa
2 Prevent the system from caching remote sources learned from a specific peer based on source and group.
CONFIGURATION mode
ip msdp sa-filter list out peer list ext-acl
Example of Verifying the System is not Caching Remote Sources
As shown in the following example, R1 is advertising source 10.11.4.2. It is already in the SA cache of R3 when an ingress SA filter is applied
to R3. The entry remains in the SA cache until it expires and is not stored in the rejected SA cache.
[Router 3]
R3(conf)#do show run msdp
!
ip multicast-msdp
ip msdp peer 192.168.0.1 connect-source Loopback 0
ip msdp sa-filter in 192.168.0.1 list myremotefilter
R3(conf)#do show run acl
!
ip access-list extended myremotefilter
seq 5 deny ip host 239.0.0.1 host 10.11.4.2
R3(conf)#do show ip msdp sa-cache
MSDP Source-Active Cache - 1 entries
GroupAddr SourceAddr RPAddr LearnedFrom Expire UpTime
239.0.0.1 10.11.4.2 192.168.0.1 192.168.0.1 1 00:03:59
R3(conf)#do show ip msdp sa-cache
R3(conf)#
R3(conf)#do show ip msdp peer
Peer Addr: 192.168.0.1
Local Addr: 0.0.0.0(639) Connect Source: Lo 0
State: Listening Up/Down Time: 00:01:19
Timers: KeepAlive 30 sec, Hold time 75 sec
SourceActive packet count (in/out): 0/0
SAs learned from this peer: 0
SA Filtering:
Input (S,G) filter: myremotefilter
Output (S,G) filter: none
Preventing MSDP from Advertising a Local Source
To prevent MSDP from advertising a local source, use the following command.
• Prevent an RP from advertising a source in the SA cache.
CONFIGURATION mode
ip msdp sa-filter list in peer list ext-acl
Multicast Source Discovery Protocol (MSDP)
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