[LARTC] tc and iptables --set-mark question

[LARTC] tc and iptables --set-mark question

[Joerg Hartmann]

Hello,

if i mark packets on my firewall with "iptables" and "--set-mark" (lets 
say .. with --set-mark 0x12 ..) can someone tell me, WHERE in the 
resulting ip packet this data is stored ?
From the examples i have seen, it seems to me that the mark can be as big 
as one Byte - is this correct ?

The next question is - is it possible to clear the statistical counters 
of "tc -s class .." back to zero ? 

thanks and regards
				Joerg
-- 
Jörg Hartmann		Tel: +49 391 40 00 125
J.Hartmann@megalearn.de
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Re: [LARTC] tc and iptables --set-mark question

[Stef Coene]

On Thursday 03 July 2003 15:12, Joerg Hartmann wrote:
> Hello,
>
> if i mark packets on my firewall with "iptables" and "--set-mark" (lets
> say .. with --set-mark 0x12 ..) can someone tell me, WHERE in the
> resulting ip packet this data is stored ?
It's stored in kernel memory.  If the packet leaves the box, the mark is gone;

> From the examples i have seen, it seems to me that the mark can be as big
> as one Byte - is this correct ?
1 byte = 2^8 = 256.  I think it can be bigger.

> The next question is - is it possible to clear the statistical counters
> of "tc -s class .." back to zero ?
No.

Stef

-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
     #lartc @ irc.oftc.net

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Re: [LARTC] tc and iptables --set-mark question

[Jose Luis Domingo Lopez]

On Thursday, 03 July 2003, at 18:30:20 +0200,
Stef Coene wrote:

> > From the examples i have seen, it seems to me that the mark can be as big
> > as one Byte - is this correct ?
> 1 byte = 2^8 = 256.  I think it can be bigger.
> 
You are correct. If I understand correctly the code in:
/usr/src/linux-2.5.73/include/linux/netfilter_ipv4/ipt_mark.h

marks are "unsigned longs", so at least 2^32 of them should be available.

Hope this helps.

-- 
Jose Luis Domingo Lopez
Linux Registered User #189436     Debian Linux Sid (Linux 2.5.73)
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