I am spanning multiple vlans as source with the destination as a single ethernet port, though I am able to see the traffic from the VLANs, I am not able to see the VLAN tag in the packet which is a key requirement for me for monitoring.
Does anyone know why the VLAN tagging is stripped or how to preserve it in the monitor session?
As far as I know VLAN tag happens only on the trunk links in order to identify which vlan each packets belongs to. If you are trying to monitor the SVI's I would assume you will not be able to see the VLAN tag in-formations on it. Try monitoring the trunk port and you should be able to see the VLAN tag information.