FC-5 iptables question

[Paul Howarth]

Johannes Christian wrote:
> maybe you can try using telnet to the specific port
> e.g $telnet server_ip 53

telnet uses TCP so that won't help for checking UDP.

The reason for opening port 53 is presumably because you have a DNS 
server running that you want to be able to access from outside?

If so, just try doing a DNS lookup on one of the zones served by your 
server from outside your network:

$ dig @your.server some.hostname

Paul.