Differences between -j MARK and -j CONNMARK

[Vinod Chandran]

Hi,

As far as I know,CONNMARK sets the mark value of the connection tracking 
entry, while MARK sets the mark value of the packet.

Omar Garcia wrote:

>Hi list,
>
>What`s the differences between these two groups of rules.?????
>In the first i use MARK --set-mark to mark packets and in the other i use CONNMARK --set-mark
>
>1.
>    # iptables -I POSTROUTING -t mangle -j CONNMARK --restore-mark
>    # iptables -I POSTROUTING -t mangle -m mark ! --mark 0 -j ACCEPT
>    # iptables -I POSTROUTING -t mangle -m ipp2p --ipp2p -j MARK --set-mark 30
>    # iptables -I POSTROUTING -t mangle -m ipp2p --bit -j MARK --set-mark 30
>    # iptables -I POSTROUTING -t mangle -j CONNMARK --save-mark
> >>>> Here u are changing the mark value of the packet while the mark value of the connection track entry remains the same. The mark value is applicable to the current packet.
>  
>
   


>2.
>    # iptables -I POSTROUTING -t mangle -j CONNMARK --restore-mark
>    # iptables -I POSTROUTING -t mangle -m mark ! --mark 0 -j ACCEPT
>    # iptables -I POSTROUTING -t mangle -m ipp2p --ipp2p -j CONNMARK --set-mark 30
>    # iptables -I POSTROUTING -t mangle -m ipp2p --bit -j CONNMARK --set-mark 30
>    # iptables -I POSTROUTING -t mangle -j CONNMARK --save-mark
>
>>>>> Here the mark value of the conntrack is changed, which is applied to the next packet ownwards.
>  
>

>Regards.
>Thanks
>
>  
>
Enjoi,
Vinod