list all connections to a specific port

drhart4000 · 05-22-2012, 09:44 PM

is there a command I can use to list all connections made to a specific port such as port 5060? I want to list the clients not the services binded to the port, can netstat do this?

Thanks,

Wayne

nikmit · 05-23-2012, 02:17 AM

cat /proc/net/ip_conntrack | grep sport=123 (or "dport=345") does the job on a debian system.
interesting to know if there is a more sofisticated way

lithos · 05-23-2012, 04:39 AM

Hi,

maybe "lsof" will help you:

Code:

root@~#>lsof -i :80
COMMAND   PID  USER   FD   TYPE DEVICE SIZE NODE NAME
httpd    1931  root    3u  IPv6   3153       TCP *:http (LISTEN)
httpd    9346 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   14809 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   16423 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   20864 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   25164 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   25581 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   26118 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   26251 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   26252 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   26253 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   26251 httpd   19u  IPv6 983561       TCP 192.168.0.10:http->1.2.3.4.dynamic.net:50453 (ESTABLISHED)
httpd   26252 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   26252 httpd   19u  IPv6 983623       TCP 192.168.0.10:http->1.2.3.4.dynamic.net:50456 (ESTABLISHED)
httpd   26253 httpd    3u  IPv6   3153       TCP *:http (LISTEN)
httpd   26253 httpd   19u  IPv6 983619       TCP 192.168.0.10:http->1.2.3.4.dynamic.net:50455 (ESTABLISHED)

see the outlined lines show connections to HTTP