Need help with ip multicast routing setup

We've got a client who needs to set up multicast routing between two sites (and between two vlans) in order for some video encoders at remote sites to find servers at the central site. I've never had experience with this. The setup looks something like:

encoders -> Cisco 4506 -> (CSME) -> Cisco 4510 -> Cisco 8540 -> Cisco

3560 -> servers

The Cisco 4506 is the default gateway for the remote site vlan, let's call it vlan 22. The Cisco 4510 is the default gateway for the central site vlan, let's call it vlan 33

Also factoring into this, a previous (before my time here) set up of ip multicasting in sparse mode was done using other remote sites using

3640 routers with the 8540 as the RP. I don't know what it was intended for, or if it was ever successfully configured, but I'm not sure it's in use any more.

Here's what's been done so far... the Cisco 4506 now has:

ip multicast-routing ip pim rp-address [the address of the 8540] interface Vlan22 ip pim sparse-dense-mode [the video encoder vendor recomended this] [there's also a ip helper-address pointing to a local server for dhcp]

The 4510 has:

ip multicast-routing ip pim rp-address interface Vlan33 ip pim sparse-dense-mode


- non-multicast traffic seems to be OK between the vlans

- the encoders never see the servers

- "show ip pim neighbor" shows no results (just headers)

- "show ip multi int vlan33" on the central site shows a large and growing number of multicast in packets, but zero out packets. Same results for vlan22 on the remote site.

Could the problem be igmp packets not getting exchanged? Like I said, I've never set up ip multicast routing before.


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What about the "-> (CSME) ->" block? Do you have PIM configured there? Basically you need a trail of PIM enabled interfaces from the source to the receivers and from each to the RP to have a hope of working.

IGMP is only significant at the receiver vlan. Elsewhere you are looking at PIM neighbours.

If you can't start at the 4506 and reach the 4510 by doing "show ip pim neighbors" and then hopping onto the neighbor address then you need to fix that.

IP Multicast Technology Overview

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Martin Gallagher

8540 is pretty old, so you may need to use a multicast seup it believes in - see what type of PIM it thinks it is running as eveything else is going to need to be consistent

it isnt going to work until you get the neighbours sorted.

do you have multicast and PIM on the interconnects between the devices?

IGMP should only be needed on the LANs with user equipment connected.

i have always used PIM v2, sparse mode and BSR, as this is covered by standards and i had to integrate non cisco kit.

Before the system is going to pass multicast each device should report that it has "contact" with the RP, and the RP for each device.

cisco have some proprietary flavours of PIM so you need to know what the various boxes

try hunting the manuals for the central 8540 and build out from there.

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Thanks for everyone's help... I think I've got ip pim set up everywhere except for one place. The encoders in question apparently don't connect directly to the 4506 at the remote site, but go to a

2960-48TC-L first. I tried to see if I could find an IOS that supports multicast routing, but I'm having trouble. Does the 2960 support multicast routing at all? I've already had to upgrade the 3560 that the servers are connected to. I've got ip pim set up everywhere else, and the other switches are seeing ip pim neighbors now.
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it is a L2 switch, so all you might want it to do is local L2 filtering if your aggregate multicast is enough to hurt a device that doesnt want to get involved.

I tried to see if I could find an IOS that supports

it doesnt even route unicast. :)

I've already had to upgrade the 3560 that

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