Re: MARK and ! question

[Sven Schuster <schuster.sven@gmx.de>]

Chris Wilson wrote:

>I think the ruleset above is wrong: the '!' should not be present here. 
>Allow me to explain the packet traversal when the same rules are used, but 
>with "!" removed:
>
>
Yeah you're right, sorry...need more coffee ;-))

>iptables -t mangle -N setmark
>iptables -t mangle -A setmark -s 193.220.70.0/27 -d 193.220.70.32/27 \
>        -j RETURN
>iptables -t mangle -A setmark -s 193.108.240.0/22 -d 193.220.70.32/27 \
>        -j RETURN
>iptables -t mangle -A setmark -j MARK --set-mark 107
>iptables -t mangle -A POSTROUTING -j setmark
>
>1. Packet enters POSTROUTING
>2. Packet jumps to "setmark" chain
>3. Packets having source address matching "193.220.70.0/27" are RETURNed 
>   to POSTROUTING
>4. Packets having source address matching "193.108.240.0/22" are RETURNed 
>   to POSTROUTING
>5. (now ONLY packets which do NOT have either of these source addresses 
>   are still in the "setmark" chain)
>6. All packets (still in the "setmark" chain) are marked with 107
>7. Packets fall off the end of the "setmark" chain and return to 
>   POSTROUTING (but they are now marked)
>8. Packets fall of the end of POSTROUTING and continue through the kernel 
>   (presumably to be delivered to a network device)
>
>Cheers, Chris.
>

Sven