RSPAN issue

[ForneyJR]

I have been unable to get RSPAN to work on 2 3550s connected together with an ISL trunk. I have a Sniffer on switch B, and a Windows PC on switch A. Unfortuneately, I found out the hard way that the reflector port takes the ISL trunk out of STP. When I configured and cabled a second trunk, I still cannot get any frames to copy to my Sniffer. I have configured this on 6500s with success, but not 3550s. Has anyone actually tested or used this with 3550s. Thanks in advance.

[dgahm · Accepted solution]

I have used RSPAN on 3550s with 802.1Q successfully.

Your reflector port should be a port that is not in use. It should not be cabled to anything, it is just a loopback port. Are you running VTP or did you manually configure the RSPAN VLAN on both switches?

If you are still having problems post your configs.

Please rate helpful posts.

[ForneyJR]

I apologize for the delayed response. I was running VTP in client/server mode.

Your suggestion corrected the issue, and I now see traffic on the Sniffer. My first attempt was using a 'disabled' port, which did not work. I had to use a port in 'notconnect' state to get the traffic to span the trunk. Thank you very much for your time.

james