REDUNDANCY AND MULTICAST

[hamid khan]

Hi All,

I am in a situation need help.

I have implemented redundancy in my network and using Multicast as well.

All ports on routers are are configured with ip pim dense-mode

Now want to know will redundancy will creat multicast loop if yes then how to overcome this issue

Second thing how can i multicast on a VLANS.

I am using STATIC Routes instead of Any dynamic routing protocols, hope it has nothing to do with multicast.

Attached is network topology.

Thanks

Hamid

[InayathUlla Sharieff · Accepted solution]

Hamid,

If you have configured the links properly(Primary & secondary) then you should not be have the issue of loop in your network.

HTH

Regards

Inayath

[hamid khan]

Thanks Inayath,

But it seems to me as multicsat Loop cause my all interfaces are configured with ip pim dense-mode .

[Ganesh Hariharan]

Hi All,

I am in a situation need help.

I have implemented redundancy in my network and using Multicast as well.

Now want to know will redundancy will creat multicast loop if yes then how to overcome this issue

Second thing how can i multicast on a VLANS.

Attached is network topology.


Thanks

Hamid

Hi Hamid,

Architecture seems to be simple and i don't think of any major loop..Are you exp. issue with this setup.

Just had a look on below link for best practices for IP Multicast with High Availability.

http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/multicast-enterprise/whitepaper_c11-474791.html

Hope that Helps..

-GI

Rate if it Helps.

[hamid khan]

But it seems to me as multicsat Loop cause my all interfaces are configured with ip pim dense-mode

Isnt it?

 How can i configure multicast for VLANs ???

[Ganesh Hariharan]

Hi Hamid,

As per definition of IP PIM Dense Mode in cisco books.

" PIM DM builds source-based multicast distribution trees. In dense mode, a PIM DM router or multilayer switch assumes that all other routers or multilayer switches forward multicast packets for a group. If a PIM DM device receives a multicast packet and has no directly connected members or PIM neighbors present, a prune message is sent back to the source to stop unwanted multicast traffic. Subsequent multicast packets are not flooded to this router or switch on this pruned branch because branches without receivers are pruned from the distribution tree, leaving only branches that contain receivers. 

When a new receiver on a previously pruned branch of the tree joins a multicast group, the PIM DM device detects the new receiver and immediately sends a graft message up the distribution tree toward the source. When the upstream PIM DM device receives the graft message, it immediately puts the interface on which the graft was received into the forwarding state so that the multicast traffic begins flowing to the receiver"

So it takes care for loop detection.

Check out the below link for multicast configuration for your reference

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/54sg/configuration/guide/mcastmls.html

Hope that Helps

-GI

Rate if it helps