EtherChannel using L3

[Jeff Harned]

Hello All,

Could use some help.  I am looking at using EtherChannel to route multicast data from a source to a destiantion unit.  I would
like to try using L3 instead of L2 using two 3560x switches.  I have made several attempts to get data to the end device but have not succeded.
I have enclosed a short version of the configuration for the two switches including a block diagram.

Thanks for any help!

Regards,

Jeff

[Peter Paluch]

Jeff,

A couple of questions:

1. Is the EtherChannel up? Can you confirm in the show ether summ that it is reported as being up with all ports actively bundled?
2. Can you ping from one switch the IP address on the other end of the EtherChannel?
3. Are you running a routing protocol over the Port-channel interfaces? This is necessary to build the routing table that will subsequently be used in multicast RPF checks and building the multicast distribution tree.
4. Do your switches see themselves as PIM neighbors? Can you confirm using show ip pim neighbor?
5. If the receives is directly connected to one of the switches, can you confirm in show ip igmp group output that the switch knows about it?
6. What does the show ip mroute say about the particular (S,G) entry along the path from the source toward the receiver? Where does it get lost or say that all interfaces are pruned?

Best regards,
Peter

[Jeff Harned]

Hi Peter,

Please review my attachments in my orginal post.  I am using pim dense-mode.

I went through your list and the Etherchannel setup is good.  However, when I got to "show ip mroute"
the data did not look correct.  I have attached the report from the Cisco6 switch that has the receivers attached from which the above command was executed from.  I do not have a understanding of what this report is telling me.

Thanks.

Regards,

Jeff

[Jon Marshall]

Jeff

On the bottom switch you have a routed L3 port with an IP of 10.1.10.1 but it shows a client connected to that port with an IP of 10.1.12.1 which is a different IP subnet.

Is this a typo ?

Jon

[Jeff Harned]

Hi Jon

No it is not a typo. The client is an end device converting in this case multicast data to serial data. Does not this client have to be in a different network to receive multicast?  I do not understand.

Thanks.

Regards,

Jeff

[Jon Marshall]

Jeff

Does not this client have to be in a different network to receive multicast?

Not sure what you are asking here.

If the client is connected directly to the port on the switch then it should have an IP from the same IP subnet.

You have a client using a different IP subnet ie. what is it's default gateway ?

Jon

[Jeff Harned]

Hi Jon

The client is directly tied to the port. I changed its address (client) to 10.1.10.2 but still it does not detect the multicast data.  I know the receiver works because it did when I was working with Inter-Vlan Multicasting Routing and setting the Cisco 6 switch as a Private Vlan.

Now I am working with EtherChannel and multicasting.  I am sure that I have a good Ethechannel config but the multicast data is not getting to the client device.  I am doing something wrong somewhere.

Thanks.

Regards,

Jeff

[Jon Marshall]

What is the source IP address of the stream ?

What is the multicast group address ?

Can you from the source of the stream ping the receiver's IP address ?

Jon

[Jeff Harned]

Hi Jon

If you look at my diagram in my original post the multicast source is from Port 5/Vlan 2 of the Cisco 4 switch.  Its routing address is 10.1.1.10.  The Port-Channel uses ports 1 and 2 on both switches.  One end has an address of 10.1.5.1 and the other end 10.1.5.2. The multicast group for the receiver  is  239.1.1.9.

Yes I can ping from the above source port to the receiver @ 0% packet loss.

Thanks.

Regards,

Jeff

[Jon Marshall]

Jeff

So the source is 10.1.1.3 as shown by your mroute output.

Can you post a "sh ip igmp group" from the bottom switch as requested by Peter.

Also I am assuming the configurations you posted are not complete ie. you have routing setup which I guess you must have if you can ping from the source to the receiver ?

Jon

[Jeff Harned]

Hi Jon

Yes the source ip is 10.1.1.3 (239.1.1.9).  I posted Peter the mroute data in my first reply to him for the bottom switch. I do not understand what you mean by static routes and dynamic routing protocol?  I am using pim-dense mode as shown in the configuration setups as shown in my original post attachments.

Thanks.

Regards,

Jeff

[Jon Marshall]

Jeff

I don't mean multicast routing, I mean IP routing.

Your switches are connected via L3 so they need to know about each other's remote subnets.

You cannot ping from the source to the receiver which suggests they don't ie. do a "sh ip route" on each switch and see if each switch knows about the subnets on the other switch.

If they don't then you need to configure routing as discussed in previous post.

PIM uses the IP routing table so without the correct routes nothing is going to work.

Jon

[Jeff Harned]

Jon

From what you are saying I have now entered a new territory!  I will have to do some reading but a little help here to get started would be helpful.  I have attached the ip routes for your viewing. Would you explain multicast routing/ip routing?

Thanks.

Regards,

Jeff

[Jon Marshall]

Jeff

Your switches are L3 devices and they only know about their own connected subnets.

But they also need to know about the subnets that are not directly connected eg. from your outputs you can see your top switch does not know about 10.1.10.0/24 so it cannot send traffic to that subnet.

This is why your source cannot ping the receiver.

So the issue is not multicast routing it is more basic ie. IP routing.

To fix it you can either setup a dynamic routing protocol to exchange routes between the two L3 switches eg. EIGRP or OSPF or you can use static routes if you only have a few subnets.

If you want to get started then you can use statics just to make sure your  multicast setup is working. So what you do is add routes for the subnets on the other switch eg. a static route would be -

"ip route 10.1.10.0 255.255.255.0 <port channel IP on bottom switch>

so the top switch knows where to send traffic to for that subnet.

You need to add routes for any non connected subnets ie. subnets that the top switch does not know about.

And then you need to add routes on the bottom switch for non connected networks pointing to the top switch IP address of the port channel.

If you do that you should then be able to ping between source and receiver.

Like I say you can use a dynamic routing protocol instead but first try statics just to see if your multicast works.

Jon

[Jeff Harned]

Hi Jon,

New day.  This is interesting. I will look into it and let you know. Curious though that
when using Inter-Vlan Multicast Routing things were working!

Thanks for help!

Regards,

Jeff