RSPAN only forwards broadcast traffic to destination port

[pehi030670]

Hello all,

I have configured an RSPAN monitoring session on a 2950 switch. I have configured a remote-span VLAN from the VTP server switch, and checked on my monitoring source switch (VTP client in the domain) that the VLAN shows up as a remote-span VLAN.

I have configured the reflector port on the client, and the destination port and source remote-vlan on the server.

No matter what VLAN I assign to the destination port - remote-span VLAN, vlan of the monitored source-port, no VLAN id at all, I only get Broadcast and multicast traffic forwarded to my monitor (wireshark).

I've seen various discussions of this over the last coupe of years, but no definitive answe (e.g. https://supportforums.cisco.com/message/544295#147017)

Has anyone got any further thoughts?

Many thanks,

Pete

[Paul Wedde]

Hi again Giuseppe and thanks very much for your help/

The Broadcast/Multicast traffic that I am seeing via the RSPAN is from the the correct switchport (IP addresses are local to this port only) so the RSPAN is working... just not all traffic is being captured.

The RSPAN VLAN is allowed on all Trunk links in between.

[mk]

Have been playing around with exactly this in the lab.

2950 as intermediate and/or destination switch..

It doesn't work as per the IOS note, not even with just Rx or Tx source.

Only random packets get through, very few of them.

Plugged in a 3550 and the issue disappeared immediately.