On Fri, 2009-11-06 at 13:13 +0000, Marco Savo wrote:
> Hello,
> configuring iptables rules,
> how I can find out if one port number I want to use is already in
> use?
> example:
>
> $IPTABLES -t nat -I zone_wan_prerouting 1 -j ACCEPT --protocol udp
> --dport ${UDP_PORT}  --destination localhost
> $IPTABLES -t nat -I zone_wan_prerouting 1 -j ACCEPT --protocol tcp
> --dport ${TCP_PORT}  --destination localhost
> $IPTABLES -t nat -I zone_wan_prerouting 1 -j ACCEPT --protocol tcp
> --dport ${TCP_HOST_PORT}  --destination localhost
>
> How I can check if these ports (UDP_PORT TCP_PORT TCP_HOST_PORT) are
> in use from another application?

----
you can use netstat - for example, I might check for port 10000...
# netstat -an|grep 10000
tcp        0      0 0.0.0.0:10000     0.0.0.0:*     LISTEN
udp        0      0 0.0.0.0:10000     0.0.0.0:*

Craig