Can jumbo Ethernet frames be VLAN-tagged?

Question

I understand that jumbo Ethernet frames are identified by a value of 0x8870 in the length/type field. (Reference: http://en.wikipedia.org/wiki/EtherType) Tagged VLAN frames are identified by a type of 0x8100.

This being the case, is it possible for a jumbo frame to be VLAN-tagged? How does that work?

Answer 1

I understand that jumbo Ethernet frames are identified by a value of 0x8870 in the length/type field. (Reference: http://en.wikipedia.org/wiki/EtherType) Tagged VLAN frames are identified by a type of 0x8100.

This being the case, is it possible for a jumbo frame to be VLAN-tagged? How does that work?

Jumbo frames don't use 0x8870; whoever edited wikipedia to say that Ethertype 0x8870 is for jumbos was over-reaching. This ethertype was proposed by an IETF draft; however, that expired and was never adopted.

IEEE strongly opposes changing the original ethernet spec, which officially limited ethernet to a 1500 byte payload. IEEE Chairman Geoff Thompson wrote a pretty thorough critique against adopting jumbo frames. In short, ethernet is more than just a frame format, it's also hardware spec; you should not attempt to separate the two.

All vlan-tagged Ethernet II frames use ethertype 0x8100

Answer 2

0x8100 just indicates the optional 802.1Q tag consisting of four bytes total. After that the actual Ethertype value and the rest of the frame follows.