Friday, June 10, 2011

Lab 149 - Auto-RP Filtering

Prerequisites: CCNP level skills.

Note!
All routers are running EIGRP protocol as well as multicast routing. All transit interfaces have been configured as Sparse-Dense-Mode.

Topology

Pic. 1 - Topology Diagram.
Icons designed by: Andrzej Szoblik - http://www.newo.pl

Task 1
Using Auto-RP, configure R1 to be RP candidate for the multicast group 224.10.10.10. R5 must be elected as the Mapping Agent. Ensure that no other router can become RP candidate for any other multicast group in the network.

Solution

Task 1
Using Auto-RP, configure R1 to be RP candidate for the multicast group 224.10.10.10. R5 must be elected as the Mapping Agent. Ensure that no other router can become RP candidate for any other multicast group in the network.

R1 Configuration:
!
interface Loopback0
 ip address 172.16.101.1 255.255.255.0
 ip pim sparse-dense-mode
!
access-list 1 permit 224.10.10.10
!
ip pim send-rp-announce loopback0 scope 16 group-list 1
!

R5 Configuration:
!
interface Loopback0
 ip address 172.16.105.5 255.255.255.0
 ip pim sparse-dense-mode
!
ip pim send-rp-discovery loopback0 scope 16
!
ip pim rp-announce-filter rp-list R1_RP group-list MULTICAST_GROUPS
!
ip pim rp-announce-filter rp-list ROUGE_RPS group-list ALL_MULTICAST_GROUPS 
!
ip access-list standard R1_RP
 permit 172.16.101.1
!
ip access-list standard MULTICAST_GROUPS
 permit 224.10.10.10
!
ip access-list standard ROUGE_RPS
 deny   172.16.101.1
 permit any
!
ip access-list standard ALL_MULTICAST_GROUPS
 deny   224.0.0.0 15.255.255.255
!

Verification:

Configuring R2 as a 'rouge' RP for a group 224.2.2.2, which should not be advertised by R5 (Mapping Agent).

R2 Configuration:
!
interface Loopback0
 ip address 172.16.102.2 255.255.255.0
 ip pim sparse-dense-mode
!
access-list 1 permit 224.2.2.2
!
ip pim send-rp-announce Loopback0 scope 16 group-list 1
!

Pic. 2 -Debug PIM Auto-RP on R5 (Mapping Agent).

Rouge RP has been filtered out.


Note!
"Use this command with caution (ip pim rp-announce-filter rp-list - JR). RPs that are matched by rp-list (allowed by a permit statement) have their multicast groups filtered by group-list. RPs that are denied (either by an explicit or implicit deny) are not subject to the filtering of their multicast groups and are "blindly" accepted as candidate RPs for all of their groups. In other words, only RPs that are permitted by rp-list have their multicast-groups filtered by group-list. All other RPs are accepted without examination".
source: http://www.cisco.com/en/US/tech/tk828/technologies_configuration_example09186a00801cb923.shtml#filter