Allow Multicast IP packets through router

[mustafa.chelik]

I have very simple network: PC-1 -> Cisco 2900 Series Router <- PC-2

PC-1 streams a video with 234.5.5.5:4000 IP/Port and PC-2 should receive and render it. But by default the router doesn't route multicast packets to other side. I found some information for this like ip multicast-routing, but it didn't work. Can someone tell me exact commands to enable multicasting in Cisco 2900 Series Router?

Thank you

[Jon Marshall]

If the network really does consist of just the router then you can run PIM dense mode so -

1) enable multicast routing ie. "ip multicast-routing"

2) under each interface on the router connecting to the PCs enable PIM ie.

int <x/y>
ip pim dense-mode

3) make sure the multicast stream has a TTL > 1 which is not something you do on the router, it is configured within the multicast software on the sending device.

Jon

[mustafa.chelik]

Thank you Jon; for your reply. I entered these commands:

• conf t
• ip multicast-routing
• int gi0/0
• ip pim dense-mode
• exit
• int gi0/1
• ip pim dense-mode
• end

But unfortunately my 234.5.5.5 UDP packets with TTL=64 could not pass through the router. I deleted every ACL and disabled every ip inspect. What do you suggest?

BTW, can I allow only specific multicast packets?

Thank you

[Jon Marshall]

What software are you using to generate the multicast stream ?

You can limit which multicast streams are allowed with an acl.

Jon

[mustafa.chelik]

I used three:

1. VLC with TTL=64 parameter
2. My custom DirectShow video streamer with TTL=64
3. A device that stream PAL camera with TTL=60

At every application I opened WireShark and verified TTL value in UDP packets.

I would be happy if you tell me how to set ACL for multicast routing (I'm newbie).

Thank you very much

[Jon Marshall]

Basically the acl is just a normal acl using multicast IPs, nothing special.

If you have confirmed the TTL I> 1 then it should have worked.

Can you post the router configuration.

Jon

[mustafa.chelik]

Actually I deleted every settings I applied before. At this moment I don't have any specific setting. I just set IP address of router interfaces (10.0.0.50 and 20.0.0.50). If you ask about any specific setting, please tell me so I post it to you.

Thank you very much Jon

[mustafa.chelik]

I set my router to it's factory settings using write erase and reload commands. After factory reset, I only changed IP address of interfaces and then input the commands you told me. It did not work again.

[Jon Marshall]

Can you post the configuration.

Jon

[mustafa.chelik]

I run show running-config command and since the result was too long, I uploaded it's file. Sorry about it.

Thank you very much Jon

By the way my interfaces' IP addresses are:

Gi0/0: 10.0.0.50 255.255.255.0

Gi0/1: 20.0.0.50 255.255.255.0

[Jon Marshall]

Can the PCs ping each other ?

Jon

[mustafa.chelik]

Yes, and they can open each other's shared folders.

[Jon Marshall]

Okay, then you should not need any more configuration than I posted.

Can you add back the multicast configuration and then test again and post the following outputs from the router -

1) "sh ip igmp membership"

2) "sh ip mroute"

Jon

[mustafa.chelik]

I set again ip multicast-routing and ip pim dense-mode commands and it did not work. So I entered the commands you requested. I attached the result. By the way, as you can see I entered sh ip igmp membership command, and then entered ip igmp membership 234.5.5.5 command and then again entered sh ip igmp membership command again.

I hope you will understand the problem.

Thank you very much for your time sir

[Jon Marshall · Accepted solution]

From the mroute output -

(10.0.0.7, 234.5.5.5), 00:09:03/00:01:49, flags: PLT
  Incoming interface: GigabitEthernet0/0, RPF nbr 0.0.0.0
  Outgoing interface list: Null

your client that is meant to receive the stream is not sending an IGMP join request to the router.

What software are you using on the client PC ?

Jon