Using Ttl To Limit The Multicast Data Sent In Sa Messages - Cisco WS-CBS3032-DEL Software Configuration Manual

Chapter 46 Configuring MSDP
Command
Step 3
access-list access-list-number {deny |
permit} protocol source source-wildcard
destination destination-wildcard
Step 4
end
Step 5 show running-config
Step 6 copy running-config startup-config
To remove the filter, use the no ip msdp sa-filter out {ip-address | name} [list access-list-number]
[route-map map-tag] global configuration command.
This example shows how to allow only (S,G) pairs that pass access list 100 to be forwarded in an SA
message to the peer named switch.cisco.com:
Switch(config)# ip msdp peer switch.cisco.com connect-source gigabitethernet0/1
Switch(config)# ip msdp sa-filter out switch.cisco.com list 100
Switch(config)# access-list 100 permit ip 171.69.0.0 0.0.255.255 224.20 0 0.0.255.255

Using TTL to Limit the Multicast Data Sent in SA Messages

You can use a TTL value to control what data is encapsulated in the first SA message for every source.
Only multicast packets with an IP-header TTL greater than or equal to the ttl argument are sent to the
specified MSDP peer. For example, you can limit internal traffic to a TTL of 8. If you want other groups
to go to external locations, you must send those packets with a TTL greater than 8.
Beginning in privileged EXEC mode, follow these steps to establish a TTL threshold. This procedure is
optional.
OL-13270-06
Purpose
(Optional) Create an IP extended access list, repeating the command as
many times as necessary.
• For access-list-number, enter the number specified in Step 2.
• The deny keyword denies access if the conditions are matched. The
permit keyword permits access if the conditions are matched.
• For protocol, enter ip as the protocol name.
• For source, enter the number of the network or host from which the
packet is being sent.
For source-wildcard, enter the wildcard bits in dotted decimal
•
notation to be applied to the source. Place ones in the bit positions
that you want to ignore.
For destination, enter the number of the network or host to which
•
the packet is being sent.
For destination-wildcard, enter the wildcard bits in dotted decimal
•
notation to be applied to the destination. Place ones in the bit
positions that you want to ignore.
Recall that the access list is always terminated by an implicit deny
statement for everything.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
Configuring MSDP
46-13