One little problem I don't understand

Costi costi at cdvultur.com
Thu Aug 10 09:55:43 CEST 2006


But still isn't iptables  *first rule wins* policy ? From what I know 
iptables runs with this policy?

Martijn Lievaart wrote:
> Vultur Constantin wrote:
>
>> Hi,
>>
>> I have a little problem understanding the way iptables does the 
>> matching of packets.
>> The problem is like this:
>> I have an subnet A.B.C.D/X which I mark it with --set-mark 1:
>>
>> $IPT -A fw-interfaces -i $INT_IF -s $INT_NET  -d A.B.C.D/X -m state 
>> --state NEW    -j ACCEPT
>> $IPT -t mangle -A PREROUTING -i $INT_IF -d A.B.C.D/X  -j MARK 
>> --set-mark 1
>>
>> and I mark the connections to port 22 ( ssh ) with --set-mark 2
>>
>> $IPT -A fw-interfaces -i $INT_IF -s $INT_NET  -p tcp --dport 22 -m 
>> state --state NEW    -j ACCEPT
>> $IPT -t mangle -A PREROUTING -i $INT_IF -p tcp --dport 22 -j MARK 
>> --set-mark 2  fw-interfaces is used as a custom chain in FORWARD.
>>
>> Now my problem is like this:
>> If I want to connect to ssh to one of the ip's from d A.B.C.D/X all 
>> my packets are set-marked with 2. The rule with d A.B.C.D/X   is 
>> above tho one with ssh.
>> Shouldn't the ssh connection to A.B.C.D/X  be marked with 1 ? If not 
>> what I am doing wrong.
>
>
> It IS marked with 1, subsequently overwritten by 2 by the second rule.
>
> HTH,
> M4
>




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