Reducing MTU to support Vlans

ehnde

I've concocted a scheme to use a GNS3 router with 2 real switches for a router on a stick lab. Bridging seems to be working fine, and I'm going to follow along with this guide: Howto: Configure Linux Virtual Local Area Network (VLAN)

But what I'm wondering is, do I need to fiddle with tap0, or just adjust the physical interface (eth0/eth0.5) to support vlans?

Second question: can I reduce the MTU from 1500 to 1482 to support the enlarged ethernet header? Some of my equipment supports a max MTU of 1500, and I figured 1482 + up to 18 bytes ought to do it. Will this actually work?

ehnde

After a bit of investigating, I *think* I've found that the MTU will be automatically calculated for me. A 4 byte VLAN tag would make the MTU 1496 + the 4 byte tag.

This makes life easy. Is my information correct?