Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

inter vlan multicasting on a 1811 router

I have a multicast source (a server) on 1 vlan and clients that need to see this traffic on 2 other vlans on the same router, but multicast doesnt seem to be routed to the client vlans. I have ip multicast enabled globally and IP PIM enabled on each vlan interface. The IOS is advanced enterprise 12.4(15)T.

Thanks in advance fro your help!

12 REPLIES
Hall of Fame Super Blue

Re: inter vlan multicasting on a 1811 router

Mike

What is the TTL of the multicast source. It may be that the TTL is not high enough to traverse the router.

Jon

New Member

Re: inter vlan multicasting on a 1811 router

Hi Jon

TTl is 33 - that should be okay.

Mike

Hall of Fame Super Blue

Re: inter vlan multicasting on a 1811 router

Mike

Yes, that should do it :)

Can you post output of

1) sh ip mroute

2) sh ip igmp membership

3) the mullticast address of the group

Jon

New Member

Re: inter vlan multicasting on a 1811 router

okay;

attached text shows the output from those commands:

- before the MC client has been started

- after the MC client has been started

- after the MC server (source) has been started.

notes:

MC address is 239.192.0.1

MC server is on vlan1

MC client is on vlan32

Mike

Hall of Fame Super Bronze

Re: inter vlan multicasting on a 1811 router

You've decided to configure the interface as sparse mode, you need a RP.

You can configure this same router to be the RP.

ip pim rp-address [ip of interface with pim enable]

New Member

Re: inter vlan multicasting on a 1811 router

Hi Jon

I have pim enabled on vlan1 vlan16 and vlan32.

Ive entered the ip pim rp-address command using the ip address of vlan1 (where the MC server is based) but im still not seeing MC appear at the client.

Mike

Hall of Fame Super Bronze

Re: inter vlan multicasting on a 1811 router

Please post the running configuration along with the show ip mroute

New Member

Re: inter vlan multicasting on a 1811 router

Hi

As attached.

Also, i put packet sniffer on the MC source (in vlan1) and do see the MC leaving the server, one every 2 seconds or so.

When I do the same on the MC receiver (which is in vlan32) I see 1 multicast packet *exactly* every 10 minutes.

Mike

Hall of Fame Super Bronze

Re: inter vlan multicasting on a 1811 router

Your router multicast configuration looks fine. Your OIL (Outgoing Interface List) from Multicast group 239.192.0.1 is pointing to the correct Vlan.

Are you able to ping 239.192.0.1 from the router ? Are you able to ping 239.192.0.1 from the receiver ?

If both answers are Yes, then I recommend looking closely to the application.

If both answers are No, then you can switch from sparse mode to dense mode and have multicast flood/prune behavior.

Are the end device(s) directly connected to this router (both source and receiver) or you have other switches in between ?

New Member

Re: inter vlan multicasting on a 1811 router

Ive been doing this testing with the sender and receiver directly connected to the router ports. pinging the multcast group address from the router does appear at the receiver. pinging from the receiver to the multicast group address did not appear at the sender.

Now im really confused!

Im willing to go with thte dense mode option - could you confirm what comands i enter on the interfaces to achieve this? I guess i wont need to point to router to an rp anymore?

Cheers

...and thanks for your help with this!

Mike

Hall of Fame Super Bronze

Re: inter vlan multicasting on a 1811 router

replace ip pim sparse with ip pim dense. Leave the RP in there, it won't be used in dense mode, but it won't hurt having it there if you decide to go back to sparse mode.

New Member

Re: inter vlan multicasting on a 1811 router

Hi there

I couldn't get this going with dense mode either. But I've found that if I disable snooping on the router the multicasts so start appearing on the target vlans. So im happy with this as I can let the LAN switches on the destination vlan deal with snooping (this works as we'd expect). Thanks for your help with this!

397
Views
0
Helpful
12
Replies