Iptables block IRC

Linux_Kidd · 05-19-2014, 11:22 AM

so, IRC can be elusive when using dst ports (egress across a fw, etc). whats the best way to block IRC, say using iptables?

TenTenths · 05-21-2014, 02:49 AM

Block everything outbound except on the ports you need, http/https/dns/smtp/etc.

Your iptables box should take care of setting up openings for ephemeral ports as required.

Linux_Kidd · 05-28-2014, 05:29 PM

Quote:

Originally Posted by TenTenths

Block everything outbound except on the ports you need, http/https/dns/smtp/etc.

Your iptables box should take care of setting up openings for ephemeral ports as required.

yikes, doesnt some IRC clients probe for outbound open ports like tcp80 & 443 ??

TenTenths · 05-29-2014, 01:54 AM

If you allow any outbound traffic through your firewall you will NEVER be able to stop someone that wants to use IRC, or indeed anything.

It's even easier these days, get cheap VPS, set SSH to listen on port 443, use SSH tunnelling. That's most basic firewalls defeated.