Date: Mon, 6 May 1996 12:11:42 -0400
From: Witz1961@aol.com
To: p8021@hepnrc.hep.net
Subject: VLAN Questions/Suggestions


Hi all - a couple of questions/suggestions:

1. Reserving values of  VLAN ID 
    
It makes sense to reserve a few values of the 16 bit VLAN ID space.  

    - Non-Valid
             I would request that one value be considered non-valid (e.g.
      "0") so that you do not need an extra bit in memory to indicate
       validity or not.  Right now, the ID is cleanly formed on 16 bits.
       An extra bit to indicate validity for internal tables forces an
       extra byte (and probably more) of storage.

    - Default VLAN
              We once talked about a VLAN that spanned the entire
      infrastructure that was never pruned.  Recommend a value reserved
      for this purpose (e.g. "1")

    - Extension valud
              Perhaps a value should be reserved for extended fields for
      the future.  Perhaps "0xffff".

2. A question about the frame length (you know, nudge, nudge).  

I would like it that a VLAN intelligent device cannot generate a VLAN frame
format (Ethernet context) at 64 bytes.  That is, it has to be at least 68
bytes if in VLAN frame format.  This makes the lookup and the translation
functions a lot easier.

Comments ? - Steve