Windows Command to check if a remote server port is opened?

I have two Windows Servers.. Server A and Server B. There is a service configured on Server A to listen on port P. Is there a way to check if the port is opened in Windows Server B irrespective of service running or not. One way is telnet ..but this would work only if the service is running and listening on Port. But, is there a way to find if the port is opened irrespective of the service state? Linux has an "nc" command to achieve the same. Do we have something similar in Windows?

Thanks.!

1 Answer

You can use netstat.exe to query for open ports.

netstat.exe:

C:\Users\user>netstat.exe /? Displays protocol statistics and current TCP/IP network connections. NETSTAT [-a] [-b] [-e] [-f] [-n] [-o] [-p proto] [-r] [-s] [-x] [-t] [interval] -a Displays all connections and listening ports. 

example netstat -a:

C:\Users\user>netstat -a Active Connections Proto Local Address Foreign Address State TCP 0.0.0.0:135 10.10.11.20:0 LISTENING TCP 0.0.0.0:445 10.10.11.20:0 LISTENING TCP 0.0.0.0:1433 10.10.11.20:0 LISTENING TCP 0.0.0.0:1801 10.10.11.20:0 LISTENING TCP 0.0.0.0:2103 10.10.11.20:0 LISTENING 

To do a remote netstat.exe you can use psexec tool (free avaiable from here)

example:

C:\Users\user>psexec \\10.10.21.145 netstat -a PsExec v2.11 - Execute processes remotely Copyright (C) 2001-2014 Mark Russinovich Sysinternals - Active Connections Proto Local Address Foreign Address State TCP 0.0.0.0:135 10.10.21.145:0 LISTENING TCP 0.0.0.0:445 10.10.21.145:0 LISTENING TCP 0.0.0.0:2701 10.10.21.145:0 LISTENING TCP 0.0.0.0:3389 10.10.21.145:0 LISTENING