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Re: How to count tx and rx bytes?

To: "David S. Miller" <davem@xxxxxxxxxx>
Subject: Re: How to count tx and rx bytes?
From: "Randy.Dunlap" <rddunlap@xxxxxxxx>
Date: Mon, 15 Dec 2003 14:40:49 -0800
Cc: greearb@xxxxxxxxxxxxxxx, netdev@xxxxxxxxxxx
In-reply-to: <20031215141729.15387fc1.davem@xxxxxxxxxx>
Organization: OSDL
References: <3FDE13AE.3050402@xxxxxxxxxxxxxxx> <20031215141729.15387fc1.davem@xxxxxxxxxx>
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On Mon, 15 Dec 2003 14:17:29 -0800 "David S. Miller" <davem@xxxxxxxxxx> wrote:

| On Mon, 15 Dec 2003 12:03:58 -0800
| Ben Greear <greearb@xxxxxxxxxxxxxxx> wrote:
| 
| > Is there an agreed upon standard for exactly what ethernet drivers
| > should be counting for rx-bytes and tx-bytes?  For example, should the
| > counters include the 4-byte FCS?  Should they include the ethernet header?
| 
| Good question.
| 
| It should be that all drivers use what skb->len ends up with at
| rx/tx time.
| 
| However, it is often faster to just let the hardware keep track
| of these statistics (tg3 is one example of a chip that can do
| this).  And sometimes these mechanisms take the FCS or whatever
| into account and this as you note makes the numbers different.


RFC 1573:
RFC 2233:
RFC 1213:
all agree that on an "interface" the number of octets received (InOctets)
is:
 The total number of octets received on the interface, including
 framing characters.

so I read that as including MAC headers and FCS.  Without reading
these, I would have said include MAC headers but not FCS.

Similar for OutOctets.

--
~Randy
MOTD:  Always include version info.

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