Hi Philip, > My config does not appear to be dropping unauthorised IPs - in my > logwatch file I am still getting lines like: > > Failed logins from: > 211.238.253.248: 54 times > > Illegal users from: > 202.110.131.27: 1 time > 211.238.253.248: 164 times I'm not familiar with logwatch. Are these SSH, telnet, other? I assume SSH, because new telnet connections are allowed in with this rule: > -A INPUT -p tcp -m state --state NEW,ESTABLISHED -m tcp --dport 25 --syn > -j ACCEPT Going through the iptables you provided, let's say with 211.238.253.248, coming in on a new connection for SSH on port 22, the first rule matched would be this one (assuming eth0 and/or eth1 are external interfaces): > -A INPUT -i eth0 -j ACCEPT > -A INPUT -i eth1 -j ACCEPT So they'd get through. As an aside, I'd recommend you 'tail -f /var/log/messages' or wherever you've got your kernel messages going in a separate window while you tune your iptables configuration. This will allow you to catch these attempts and make rules for them faster than waiting to see them show up in a log the next day. Cheers, Drew. > *filter > :INPUT DROP [0:0] > :FORWARD DROP [0:0] > :OUTPUT DROP [0:0] > -A INPUT -i lo -j ACCEPT > -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT > # -A INPUT -p tcp -i eth0 --dport 22 --sport 1024:65535 -j LOG > --log-prefix "ssh connect:" > -A INPUT -p tcp -m tcp -s 149.171.173.169 --dport 22 -j ACCEPT > -A INPUT -p tcp -m tcp -s 203.166.81.114 --dport 22 -j ACCEPT > # -A INPUT -p tcp -m state --state NEW,ESTABLISHED -m tcp --dport 22 -j > ACCEPT > -A INPUT -p tcp -m state --state NEW,ESTABLISHED -m tcp --dport 25 --syn > -j ACCEPT > -A INPUT -p tcp -m state --state NEW,ESTABLISHED -m tcp --dport 53 --syn > -j ACCEPT > -A INPUT -p tcp -m state --state NEW,ESTABLISHED -m tcp --dport 80 -j > ACCEPT > -A INPUT -p tcp -m state --state NEW,ESTABLISHED -m tcp --dport 3128 > --syn -j ACCEPT > -A OUTPUT -o lo -j ACCEPT > -A OUTPUT -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT > -A INPUT -i lo -j ACCEPT > -A INPUT -i eth0 -j ACCEPT > -A INPUT -i eth1 -j ACCEPT > -A INPUT -p udp -m udp -s 149.171.173.169 --sport 53 -d 0/0 -j ACCEPT > -A INPUT -p udp -m udp -s 203.166.81.114 --sport 53 -d 0/0 -j ACCEPT > -A INPUT -p tcp -m tcp --syn -j REJECT > -A INPUT -p udp -m udp -j REJECT > -A INPUT -j LOG --log-level alert > -A INPUT -j LOG --log-prefix "Dropped: " > COMMIT -- Drew Leske :: Systems Group/Unix, Computing Services, University of Victoria dleske@xxxxxxx / +1250 472 5055 (office) / +1250 588 4311 (cel)
