Dear all,
I never really understood this:
I always thought that VLAN tagging adds few bytes to the packet, so how come the MTU is the same? Is my network now effectively running at 1496 MTU?
Can anybody explain?
Thank you
I always thought that VLAN tagging adds few bytes to the packet, so how come the MTU is the same? Is my network now effectively running at 1496 MTU?
The VLAN tag lives inside the ethernet header and dies not eat into the ethernet payload, where the default maximum still stays at 1500... (this is not 100% correct for small packets the minimal L2 ethernet frame size stays at 64 octets, resulting in 4 bytes less space for payload, but that really has no bearing on the MTU). The same is true for dual VLAN tags... Have a look at:
and
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ok thx, so its part of the header, but then the max packet size is bigger if its a tagged frame? why did they do it like this? I assume the max is there to limit buffer sizes or something?
I guess you would need to talk to the IEEE group that actually specified that, I have no information about the rationale behind that design decision, sorry
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Ah no worries, thx for the info!
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