Re: Problem with iptables -A FORWARD -j DROP

[Bernd Podey <Bernd.Podey@gmx.de>]

Gabriel Güeto wrote:
> Hello, I'm installing a bridge-firewall an all is OK, but whe I deny all 
> the 'FORWARD' traffic this rule deny all the traffic included the 
> 'ACCEPT' rules. Mi Kernel is 2.4.18
> and i installed itables 1.2.5-3. My script is:
>  
> iptables -F FORWARD
> iptables -F INPUT
> iptables -F OUTPUT
>  
> iptables -A FORWARD -p icmp -s 89.0.0.0/24 -d 89.0.0.55/32 -j ACCEPT
>  
> iptables -A FORWARD -j DROP
>  
>  
>  
> If I quit the las line it's all OK, if I deny 'ping' it's OK, but if I 
> put the last line all ping are deny.
>  
> Can somebody help me. I'm sorry for mu poor English.
>  
> Gabriel.
Hello!

You have to allow both communication directions!

Try the following:
iptables -A FORWARD -p icmp -s 89.0.0.0/24 -d 89.0.0.55/32 -j ACCEPT
iptables -A FORWARD -p icmp -s 89.0.0.55/32 -d 89.0.0.0/24 -j ACCEPT

iptables -A FORWARD -j DROP

and everything will work fine

Bernd