identifying vlan packets using tcpdump

I'm trying to figure out the vlan tagged packets that my host receives or sends to other hosts. I tried

tcpdump -i eth1 vlan 0x0070

But it didnt work. Has anyone tried to view the vlan packets through tcpdump before? Couldn't find much help searching the web!

Solution 1:

If your host is connected to an access port, the switch will likely strip the VLAN tag off before it reaches your host. As a result, running TCPDump on the host in question will never see the VLAN tags.

You would need to setup a SPAN port and/or introduce a network tap into your network somewhere to grab traffic before the tags are dropped off the packets in order to see them in a network dump/trace.