How to properly loop in a switch?

[TheGreatDoc]

Hi All,

Another dumb question from me! 

I'm sending a MPTS multicast from our main office to a secondary network off the limits of our main F.O. network.

Between the 2 building there are 2 radio PtP, so I need to know if in the secondary network the multicast is going well.

What I did? Im sending it in vlan 22, in the secondary building I'm looping the switch from v22 to v23 and then trying to get the multicast back to the main building.

Of course, this is not working. Both ports in secondary building are access but Im recieving a "native vlan mismatch".

How can I properly do this?

[Dieselboy]

I don't know about "properly" but disabling CDP on the ports where you are bridging the VLANs will get rid of the native VLAN mismatch issues, if I remember correctly.

[sergeyrar]

hi,

Perhaps STP blocks one of your ports (either the looped one, or the remote connection).
So you can try disabling STP (which will cause lot of trouble because your multicast traffic will just loop endlessly),
Or you can just test it by sending multicast traffic from the remote end on VLAN23.

[TheGreatDoc]

None of the above works.

I need to check and know if the multicast traffic is recieving correctly on secondary building from the main building.

The only I though was to make a loop in the switch from one vlan to another, but cant recieve the multicast stream in the main building from the return vlan.

How I could do this?

[NetworkGroover]

What do access ports have to do with native VLAN mismatches??

I've done something somewhat similar in what's called a "snake test".  You have one port coming in, then you loop every port, incrementing the VLAN each time, then the traffic comes out a port at the end.  I know this works - I included a picture from my testing notes.  I suspect you have something else going on but not being there and with the details provided thus far - not a clue.

[SimonV]

What do access ports have to do with native VLAN mismatches??

CDP will advertise the access VLAN as the native VLAN.

[TheGreatDoc]

The remote switch in question is SF302-08. I know, is not the best switch but it does what we need.

I've disabled CDP and STP but still cant recieve multicast return back.

Time ago, what we did was to recieve the multicast in the remote building and then re-encode it and return back, but we need those encoders and I thoug i could recieve the same multicast that im sending doing a loop in different vlans.

Buuuuut, is not working How I could debug that?

[sergeyrar]

Where is the receiver?
Is IGMP snooping enabled?

[TheGreatDoc]

Hi, there is no IGMP at all.

Here is a drawing of what I mean and what I want to do.

[TheGreatDoc]

Nobody?

[Dieselboy]

This sounds messy.

Does the radio link know how to process multicast? My guess is that it's dropping it. Which is probably a good thing Would need to look into the transceivers at both ends.

[TheGreatDoc]

No no, radiolinks works perfect.

I'll try to explain again.

Im sending the multicast in the V20 and Im recieving it in the remote building in ports 4 and 6.

In the port 6 I have the "receiver" of the multicast. Now, I want to know if the multicast is working well or if it is having any trouble so I create the vlan 23 to return the vlan.

Port 4(v20) is looped to port 5 (v23) and that is what is not working. I cant recieve the multicast in the main building in the v23.

[icecream-guy]

maybe you could post some related configs?

[zarawatsonn]

In my opinion my enabling th IMGP, you can fix your problem.

[Dieselboy]

Looking at the diagram and what you're trying to do, apart from bad design and making my face pull odd shapes, I can't see a reason why it wont work that way. But we don't know where the connection is breaking, do the radio links know how to VLAN? Are they doing anything odd with the traffic? What STP version are you running (I guess none, now)..

Regarding how you can debug it, well I would check that the multicast is getting to the remote switch as you think that it is. Then I would make sure that after you loop the VLAN on the remote switch that the multicast is going to come out of the radio link back to the main office. I would do a span port there and see if the traffic is indeed being sent out to the radio link. Then do the same span port test at the main office and go from there.

Basically, start at one end and work your way through