I am trying to secure my vps server running ubuntu HardyHeron (8.04 lts). I am using iptables to block almost all incoming traffic. I wish to allow the following:
- Web traffic (80 & 443)
- mail traffic (incoming and outgoing, 25?)
- all traffic from my home pc (I have a static ip)
Everything works great except mail. I have not yet tested incoming mail, but outgoing mail appears to be blocked when I load the chain. I have several web pages that email confirmations and those confirmations are blocked when I load the rules, but work fine when I don't have any rules. here are the rules (output from iptables -L)
target prot opt source destination ACCEPT tcp -- anywhere anywhere tcp dpt:www ACCEPT tcp -- anywhere anywhere tcp dpt:https ACCEPT tcp -- anywhere anywhere tcp dpt:smtp ACCEPT all -- 18.104.22.168 anywhere #fake ip, but allows all traffic from my home pc LOG all -- anywhere anywhere limit: avg 5/min burst 5 LOG level debug prefix `iptables denied: ' DROP all -- anywhere anywhere Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination
I don't understand why the mail is blocked so I'd appreciate help on that and also what specifically to add to allow the outgoing mail.