Re: [PATCH] 802.1p priority (fixed)

From: Jeremie Le Hen (jeremie_at_le-hen.org)
Date: 01/23/05

  • Next message: Brooks Davis: "Re: [PATCH] 802.1p priority (fixed)" 
    Date: Sun, 23 Jan 2005 12:22:19 +0100
To: Brooks Davis <brooks@one-eyed-alien.net>

    > > Having the possibility to test and set the 802.1p or TOS values
    > > separately would avoid making a "trust"/"override" subtlety and will
    > > obviously make it more flexible.
    >
    > I agree on this point. The one thing to be careful of is that 802.1p
    > priorities and TOS values work rather differently in that TOS values fit
    > in to an existing field of the packet and 802.1p values require
    > modifications to the header and adding data between the header and the
    > real body, possiably with a resuling reduction in MTU (though what
    > you're doing trying to use 802.1p priority with crappy nic I don't know
    > :-).

    I do not understand your point here. TOS is indeed an existing field
    of the IPv4 header but AFAIK, this is the same for the 802.1p header [1].
    There are already 3 bits reserved for priority (802.1p) near the 802.1q
    field which are both inside what they call "Tag Control Information".

    Regards,

    [1] http://www.networkdictionnary.com/protocols/8021p.php 

    -- 
Jeremie Le Hen
jeremie@le-hen.org
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  • Next message: Brooks Davis: "Re: [PATCH] 802.1p priority (fixed)"

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