Re: verifying set-mark

[Matt Zagrabelny <mzagrabe@d.umn.edu>]

[-- Attachment #1: Type: text/plain, Size: 2639 bytes --]


On Fri, 2008-02-22 at 12:53 -0800, Casey Scott wrote:
> Good suggestion. Tried just tried that. Traffic gets logged, but 
> the mark is not set. E.g. (from dump)
> 
> Feb 22 12:50:52 tomcat kernel: IN= OUT=eth0 SRC=66.93.87.2 
> DST=192.168.1.7 LEN=1500 TOS=0x00 PREC=0x20 TTL=54 ID=4397 
> DF PROTO=TCP SPT=80 DPT=4322 WINDOW=17520 RES=0x00 ACK URGP=0
> 
> Feb 22 12:50:52 tomcat kernel: IN=eth0 OUT=eth1 SRC=192.168.1.7 
> DST=66.93.87.2 LEN=40 TOS=0x00 PREC=0x00 TTL=127 ID=18031 DF 
> PROTO=TCP SPT=4322 DPT=80 WINDOW=64240 RES=0x00 ACK URGP=0
> 
> Feb 22 12:50:52 tomcat kernel: IN= OUT=eth0 SRC=66.93.87.2 
> DST=192.168.1.7 LEN=1500 TOS=0x00 PREC=0x20 TTL=54 ID=4398 
> DF PROTO=TCP SPT=80 DPT=4322 WINDOW=17520 RES=0x00 ACK URGP=0
> 
> 
> Notice all the TOS is still 0x00. I am setting marks to 3 or 4 
> depending on traffic type.

AFAIK, setting TOS is not the same as marking. [goes to check]
The man page confirms that.

> Casey
> 
> ----- "Rob Sterenborg" <rob@sterenborg.info> wrote:
> 
> > > How can I detemine whether or not a iptables set-mark operation
> > > is working? iptables -t mangle -nvL shows packets matching the
> > > rules with the set-mark. However, with a tcpdump -vvv -i
> > > <interface>
> > > I can not see the mark. I am looking at the tos field, and I
> > > don't see a tos field matching the marks I am trying to set.
> > 
> > Did you try to match the mark in a subsequent rule and LOG the packet
> > when the rule hits?
> > See also man iptables:
> > 
> > mark
> > This module matches the netfilter mark field associated with a packet
> > (which can be set using the  MARK  target below).
> > --mark value[/mask] Matches packets with the given unsigned mark value
> > (if a mask is specified, this is logically ANDed with the mask before
> > the comparison).
> > 
> > 
> > Grts,
> > Rob
> > 
> > 
> > -
> > To unsubscribe from this list: send the line "unsubscribe netfilter"
> > in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> -
> To unsubscribe from this list: send the line "unsubscribe netfilter" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
-- 
Matt Zagrabelny - mzagrabe@d.umn.edu - (218) 726 8844
University of Minnesota Duluth
Information Technology Systems & Services
PGP key 1024D/84E22DA2 2005-11-07
Fingerprint: 78F9 18B3 EF58 56F5 FC85  C5CA 53E7 887F 84E2 2DA2

He is not a fool who gives up what he cannot keep to gain what he cannot
lose.
-Jim Elliot

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 189 bytes --]