Hello,
we’re using PG and Application Server (JBoss) on separate CentOS servers with Cisco PIX in between. On DB side is iptable with following relevant rules:
1. -A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
2. -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp -s aaa.bbb.ccc.ddd --dport 5432 -j ACCEPT
3. -A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
I was wondering when these rules are not OK for our environment. It seems that rules 1 and 2 sometimes pass packets and therefore these packets are rejected. Such connection is then in some weird state, doesn’t communicate (obviously – packets are dropped) and psql (or JBoss) connection is blocking for a long time (at least few hours).
Everything seems to be OK when I have changed rule 2 to “-A RH-Firewall-1-INPUT -m tcp -p tcp -s aaa.bbb.ccc.ddd --dport 5432 -j ACCEPT“.
I’m really confused – what other states are possible for iptables except ESTABLISHED, RELATED or NEW? In iptables manpage is only INVALID, but why is this state emerging?
Any idea?
Lukas
