[CentOS] iptables rules

m.roth at 5-cent.us m.roth at 5-cent.us
Mon Mar 29 21:48:01 UTC 2010


I've got a server with several ip's on eth0. I want to block all traffic
*except* to port 80 on them, but not on any other IPs, so that
eth0 is www.xxx.yyy.zzz
eth0:1 is www.xxx.yyy.ggg
eth0:2 is www.xxx.yyy.hhh

I've tried
-A RH-Firewall-1-INPUT -p tcp -d www.xxx.yyy.ggg --dport ! 80 -j DROP
-A RH-Firewall-1-INPUT -p tcp -d www.xxx.yyy.hhh --dport ! 80 -j DROP

and restarted (and several variants of this). iptables-save displays

*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [769:48207]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -d  www.xxx.yyy.ggg -p tcp -m tcp ! --dport 80 -j DROP
-A RH-Firewall-1-INPUT -d www.xxx.yyy.hhh -p tcp -m tcp ! --dport 80 -j DROP
-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT
<...>
and I notice it puts the ! in front of the --dport, but has no complaints.

However, I can telnet to www.xxx.yyy.hhh 443. What's wrong with the rules?

         mark



More information about the CentOS mailing list