Add a second RP for a multicast group

[dikatanou]

Hi,

I have already an RP for my system:

ip pim rp-address 192.168.15.253

But I want for the multicast address 225.4.1.81a different RP

So I have added

ip access-list standard grpmulticast
 permit 225.4.1.81
 

ip pim rp-address 172.26.3.50 grpmulticast override

ip mroute 82.113.0.0 255.255.224.0 172.26.3.50

However I still have the same RP(see below):

cs#sh ip mroute 225.4.1.82
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
       L - Local, P - Pruned, R - RP-bit set, F - Register flag,
       T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
       X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
       U - URD, I - Received Source Specific Host Report,
       Z - Multicast Tunnel, z - MDT-data group sender,
       Y - Joined MDT-data group, y - Sending to MDT-data group,
       V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
 Timers: Uptime/Expires
 Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 225.4.1.82), 02:37:13/stopped, RP 192.168.15.253, flags: SP
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list: Null

(x.x.x.x, 225.4.1.82), 02:37:13/00:02:59, flags: PT
  Incoming interface: Vlan120, RPF nbr 192.168.120.240, Mroute
  Outgoing interface list: Null

Can please someone help on this as I don't hve experience with multiple RP?

Thanks!

Dimitra

[dikatanou]

Would appreciate any help on this

:)

[sumit menaria · Accepted solution]

Well the override option overrides the RP mapping learnt by the dynamic RP mapping method.

I have worked on such scenario for one of my enterprise clients .

We used static RP mapping since the network was not much big.

ip pim rp-address 2.2.2.2 10
ip pim rp-address 1.1.1.1 20

access-list 10 permit 224.6.6.6
access-list 20 permit 224.7.7.7

R4#sh ip mroute
(*, 224.6.6.6), 00:28:18/00:02:44, RP 2.2.2.2, flags: SJCL
  Incoming interface: FastEthernet1/0, RPF nbr 192.168.34.3
  Outgoing interface list:
    Loopback10, Forward/Sparse, 00:28:18/00:02:44

(*, 224.7.7.7), 00:00:03/00:02:56, RP 1.1.1.1, flags: SJCL
  Incoming interface: FastEthernet1/0, RPF nbr 192.168.34.3
  Outgoing interface list:
    Loopback0, Forward/Sparse, 00:00:03/00:02:56

(*, 224.0.1.40), 00:33:09/00:02:47, RP 0.0.0.0, flags: DCL
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list:
    FastEthernet1/0, Forward/Sparse, 00:33:09/00:02:47

Can you let me know the access-list being used for the exiting RP.If that list permits the group 225.4.1.81 for existing RP ,then new RP may not take this depending on the priorities.

Also can you try executing clear ip mroute 225.4.1.81 and check the results.

Cheers!

Sumit

thebetternetwork.com

[dikatanou]

Thanks both! :)

David, the typo was on show ip mroute. Istill get the same result in 225.4.1.81:

(*, 225.4.1.81), 1d10h/stopped, RP 192.168.15.253, flags: SP
  Incoming interface: Null, RPF nbr 0.0.0.0
  Outgoing interface list: Null

(82.113.13.97, 225.4.1.81), 19:13:55/00:02:58, flags: PT
  Incoming interface: Vlan120, RPF nbr 192.168.120.240, Mroute
  Outgoing interface list: Null

Sumit:
There is not ACL for the existing RP, so that probably means that allows everything so maybe the new one does not take priority.

Do you suggest adding an ACL for the existing as well?

[David Trocki · Accepted solution]

You could try applying an ACL to your existing static RP statement like so...

access-list 10 deny 225.4.1.81

access-list 10 permit any

ip pim rp-address 192.168.15.253 10

[sumit menaria]

I tried it RP without the ACL for the first RP 2.2.2.2 and discussed before it dint seem to work.

RP Mapping takes 224.0.0.0/4 for 2.2.2.2 and RP-1.1.1.1 for static ,but that does not change the mroute table.

Only option left would be deny the group used by RP-1.1.1.1 in the acl setup for 2.2.2.2,which is similar to the suggestion by David.

*********

ip pim rp-address 2.2.2.2

R4#sh ip mroute
IP Multicast Routing Table

(*, 224.6.6.6), 00:15:08/00:02:47, RP 2.2.2.2, flags: SJCL
  Incoming interface: FastEthernet1/0, RPF nbr 192.168.34.3
  Outgoing interface list:
    Loopback10, Forward/Sparse, 00:15:08/00:02:40

(*, 224.7.7.7), 00:04:09/00:02:17, RP 2.2.2.2, flags: SJCL
  Incoming interface: FastEthernet1/0, RPF nbr 192.168.34.3
  Outgoing interface list:
    Loopback0, Forward/Sparse, 00:04:09/00:02:17

ip pim accept-rp 1.1.1.1 10

ip access-list standard 10
permit 224.6.6.6 0.0.0.0 log

R4#sh ip pim rp mapping
PIM Group-to-RP Mappings

Group(s): 224.0.0.0/4, Static
    RP: 2.2.2.2 (?)
Acl: 10, Static
    RP: 1.1.1.1 (?)

R4#sh ip mroute

(*, 224.6.6.6), 00:09:05/stopped, RP 2.2.2.2, flags: SJCLF
  Incoming interface: FastEthernet1/0, RPF nbr 192.168.34.3
  Outgoing interface list:
    Loopback10, Forward/Sparse, 00:09:05/00:02:29

(*, 224.7.7.7), 00:09:20/00:02:53, RP 2.2.2.2, flags: SJCL
  Incoming interface: FastEthernet1/0, RPF nbr 192.168.34.3
  Outgoing interface list:
    Loopback0, Forward/Sparse, 00:09:20/00:02:53

Cheers!

Sumit

Please rate if helps!

thebetternetwork.com

[dikatanou]

I tested it finally today and it worked.

Fantastic, thanks both.

The correct configuration was finally

ip pim rp-address 172.26.3.50 grpmulticast
ip pim rp-address 192.168.15.253 bmulticast

ip route 172.26.3.50 255.255.255.255 192.168.120.240
!

ip access-list standard bmulticast
 remark original RP point
 deny   225.4.0.0 0.0.0.255
 permit any

ip access-list standard grpmulticast
 permit 225.4.0.0 0.0.0.255

And i finally get the result:

(*, 225.4.0.9), 00:00:13/00:02:52, RP 172.26.3.50, OIF count: 1, flags: SJC
  (82.113.13.98, 225.4.0.9), 00:00:13/00:02:54, OIF count: 1, flags: JT

Thank you!!

[David Trocki]

It looks like you just made a typo.... in your acl you specify .81 rather than .82.

ip access-list standard grpmulticast
 permit 225.4.1.81