Firewall still blocking port 53 despite listing otherwise?
- by Tom
I have 3 nodes with virtually the same iptables rules loaded from a bash script, but one particular node is blocking traffic on port 53 despite listing it's accepting it:
$ iptables --list -v
Chain INPUT (policy DROP 8886 packets, 657K bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT all -- lo any anywhere anywhere
2 122 ACCEPT icmp -- any any anywhere anywhere icmp echo-request
20738 5600K ACCEPT all -- any any anywhere anywhere state RELATED,ESTABLISHED
0 0 ACCEPT tcp -- eth1 any anywhere node1.com multiport dports http,smtp
0 0 ACCEPT udp -- eth1 any anywhere ns.node1.com udp dpt:domain
0 0 ACCEPT tcp -- eth1 any anywhere ns.node1.com tcp dpt:domain
0 0 ACCEPT all -- eth0 any node2.backend anywhere
21 1260 ACCEPT all -- eth0 any node3.backend anywhere
0 0 ACCEPT all -- eth0 any node4.backend anywhere
Chain FORWARD (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
Chain OUTPUT (policy ACCEPT 15804 packets, 26M bytes)
pkts bytes target prot opt in out source destination
nmap -sV -p 53 ns.node1.com // From remote server
Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2011-02-24 11:44 EST
Interesting ports on ns.node1.com (1.2.3.4):
PORT STATE SERVICE VERSION
53/tcp filtered domain
Nmap finished: 1 IP address (1 host up) scanned in 0.336 seconds
Any ideas?
Thanks
