Listener freeware that listens on multiple / a range of ports

I have plenty of firewall rules to test.

I'm currently using WinSSHD & Udp Test tool to listen on
destination Win 2012 servers & from the source servers,
used MS Portquery to test.

Portquery is fine in that it allows me to specify a range
of Tcp+Udp ports.

However, at destination end, WinSSHD & Udp Test tool
can only bind or listen to one port at a time so this is not
productive if I have thousands of ports to test.

Is there a tool that could verify that firewall rules have been
permitted correctly without the need to set up a listener at
the destination (as currently the Apps team haven't got the
time to install their actual apps yet) & I need to test in

Alternatively, suggest a couple of freeware that could be set
to listen on a range of ports (or  can be selected number of
ports separated by say, commas) for Windows 2008/2012
Who is Participating?
edster9999Connect With a Mentor Commented:
Ok looks like I was wrong on that (sorry).  Here is another snip from the help page :

-l      Used to specify that nc should listen for an incoming connection
             rather than initiate a connection to a remote host.  It is an
             error to use this option in conjunction with the -p, -s, or -z
             options.  Additionally, any timeouts specified with the -w option
             are ignored.

So you cannot listen on multiple ports with a single instance.
The only thing you could do would be to spawn off a different one for each port and dump the output into a separate file for each
JohnConnect With a Mentor Business Consultant (Owner)Commented:
For packet sniffing (which is what you want here), Wireshark ( is free and it works. CommView ( is a commercial packet sniffer and not free. I use the latter, but both will work.

.... Thinkpads_User
sunhuxAuthor Commented:
What's needed is something simple/easy-to-use  for testing
 the firewall rules.

Portqry & nmap are rather easy & not resource intensive.
I can't possibly install wireshark on a server that's going
to be production in 2 months' time & Wireshark is rather
not easy to use to test firewall rules.  Portqry doesn't
need installation & it could just run directly from disk
(without altering registry).  So can nmap but these are
tools that I'll run from the Source IP.  What I need are
tools that run on the Destination IP that listen on the
required ports : Udptest tool & WinSshd (which allows
me to specify the port to listen on) helps in my case
if it's just a small handful of ports but if there's a big
range of ports, then Udptest & WinSshd becomes
Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

edster9999Connect With a Mentor Commented:
You need netCat.
It is a unix took but people have ported it to work under windows.

It listens on port(s) and dumps what it receives to the screen or a file.
sunhuxAuthor Commented:
Does netCat has a version that runs on the 64bit Win2012?
sunhuxAuthor Commented:
sunhuxAuthor Commented:
Unfortunately one of them only listen on Tcp port (& one
port at a time) while the other does not run on Win2008
or Win2012
edster9999Connect With a Mentor Commented:
Netcat just needs to be compiled to run on whatever platform you want.
There are a few people who have done it in 64Bit code compilers :

It has not seen much testing in the platform - but it is very stable tested platform so it shouldn't cause much of an issue.
I wouldn't run it on a live production server.... not one taking production traffic anyway.
Take a server offline and test it on that.
sunhuxAuthor Commented:
Ok I've seen a copy of nc64.exe that works in the zip.

Lastly, this netcat only listen on one port at a time only.
Can I run it multiple times to listen on multiple ports?
(I guess if I have hundreds of ports, I'll need to write
 a script to do this?)
edster9999Connect With a Mentor Commented:
I use the linux version - so you'll have to look it up to see if the windows one is the same (but it probably is, as they are built off the same code base)

ed:$ nc /?

This is nc from the netcat-openbsd package. An alternative nc is available
in the netcat-traditional package.
usage: nc [-46DdhklnrStUuvzC] [-i interval] [-P proxy_username] [-p source_port]
        [-s source_ip_address] [-T ToS] [-w timeout] [-X proxy_protocol]
        [-x proxy_address[:port]] [hostname] [port[s]]


     port[s] can be single integers or ranges.  Ranges are in the form nn-mm.
     In general, a destination port must be specified, unless the -U option is
     given (in which case a socket must be specified).
sunhuxAuthor Commented:
Can't quite get the syntax to listen/bind on multiple ports to
work on Windows version:

D:\ncatWin7\netcat-1.11>nc -l -p 333-335 -e cmd.exe
D:\ncatWin7\netcat-1.11>nc -l -p 333,335 -e cmd.exe

while netstat below only shows it listens on 1 port ie Tcp333:
D:\>netstat -an | find ":33"
  TCP                LISTENING
  TCP               LISTENING

D:\>netstat -an | find ":33"
  TCP                LISTENING
  TCP               LISTENING
sunhuxAuthor Commented:
It appears that it's only in client mode that nc can be
made to specify a range of source ports;  in server/
listening mode, it doesn't appear to let me specify
a range of ports to listen on.

Can you verify if this is also the case for the Linux/UNIX
version of nc?
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.