VSPAN over RSPAN - Configuring RSPAN source on a VLAN also capture traffic in that VLAN that comes in on active trunk ports?

[Bradley Pitt]

Hi, 

I have been looking online but I cannot find an answer (or answer I understood). 

We are running RSPAN at multiple sites to capture VoIP traffic for recording. 

This usually works fine, however at one site we are having this issue with duplicate traffic being received by the recording server. 

I am trying to workout if VSPAN sessions running over RSPAN also captures traffic on trunk ports (with the source VLAN) on the switch where we are running VSPAN and if this would be causing duplicate packets to be received.

Please see my diagram for a visual explanation of our setup and how traffic is flowing. 

Would this be causing duplicate traffic? 

 

[balaji.bandi]

VSPAN (Hope you mean VLAN SPAN right ?)

high level yout view correct, you looking source vlan 100 and RSPAN to remote, and capturing interface G1/0/1

not sure what devices these, check basic config here :

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/12-2_55_se/configuration/guide/3750xscg/swspan.html#12866

[Bradley Pitt]

Hi Bajaji, 

Yes I meant VLAN SPAN (VLAN RSPAN?). I will modify that above. 

Basically we want to know if the traffic is being captured and duplicated when it crosses the trunk between the switches and then AGAIN when it crosses the port that connects to the edge device.  

[balaji.bandi]

Basically we want to know if the traffic is being captured and duplicated when it crosses the trunk between the switches and then AGAIN when it crosses the port that connects to the edge device.

not sure if i understand correctly, when you do RSPAN the source traffic usie VLAN X to go to remote switch and termniated at Switch post where you lokking to Mirror te traffic.

you mean duplciate is mirror ?