Re: Any 1U - 2U Ethernet switches that can handle 4K VLANs?

[Alexei Roudnev]

So what?  Is is a sugnificant drawback? I do not think so. Both ISL and
802.1q require special interface cards (with extended frame size), and I do
not see any reason, why 26 bytes vs 4 bytes makes big difference. /May be,
the only pro for 802.1q tagging is it's possible  implementation on the old
interface cards, which did not allowed extra 30 bytes but allowed extra 4
bytes/.

I am no saying that ISL is better tha 802.1q, but 802.1q is not much better
than ISL, and (in some cases) is even worst.


----- Original Message ----- 
From: <sthaug@nethelp.no>
To: <alex@relcom.net>
Cc: <nanog@merit.edu>
Sent: Monday, January 26, 2004 9:10 AM
Subject: Re: Any 1U - 2U Ethernet switches that can handle 4K VLANs?


> > ISL _DOES NOT CHANGE_ packet size.
>
> An 802.1q tag adds 4 bytes to the Ethernet frame.
>
> ISL encapsulation adds 30 bytes to the Ethernet frame.
>
> Steinar Haug, Nethelp consulting, sthaug@nethelp.no