Hi, I have type a "shorewall (4.5.4) drop x.x.x.x", an malware IP that
constantly tried to access my DNS, but the IP was not blocked
immediately.

> -A dynamic -s x.x.x.x/32 -j DROP
>  ....
> -A INPUT -i eth1 -j net2fw 
> -A net2fw -m conntrack --ctstate INVALID,NEW -j dynamic 
> -A net2fw -p tcp -j tcpflags 
> -A net2fw -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT 
> -A net2fw -p udp -m udp --dport 1194 -j ACCEPT 
> -A net2fw -d y.y.y.y/32 -p icmp -m icmp --icmp-type 8 -j ACCEPT 
> -A net2fw -d y.y.y.y/32 -p tcp -m tcp --dport 22 -j ACCEPT 
> -A net2fw -d y.y.y.y/32 -p tcp -m multiport --dports 80,443 -j ACCEPT 
> -A net2fw ! -s x.x.x.x/32 -d y.y.y.y/32 -p tcp -m tcp --dport 53 -j ACCEPT 
> -A net2fw ! -s x.x.x.x/32 -d y.y.y.y/32 -p udp -m udp --dport 53 -j ACCEPT 

This probably happens because the connection is always active:

> # shorewall show connections |grep x.x.x.x
> ipv4     2 udp      17 178 src=x.x.x.x dst=y.y.y.y sport=80 dport=53 
> src=y.y.y.y dst=x.x.x.x sport=53 dport=80 [ASSURED] mark=0 secmark=0 use=2
> 
and the rule "dynamic" is applies only to new connections "conntrack
--ctstate INVALID,NEW"

In addition, the rule:

"-A net2fw -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT"

makes the connection to be accepted without meeting the rule would not
allow access to DNS:

"-A net2fw ! -s x.x.x.x/32 -d y.y.y.y/32 -p udp -m udp --dport 53 -j ACCEPT"

What am I doing wrong?

It's possible, after a shorewall drop IP, delete the alive connection
for the dropped IP?

Many thanks for reply

-- 
Dario Lesca - sip:[email protected]
(Inviato dal mio Fedora Linux)


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