Accessible ports

[Invisible]

Is there a simple test I can do to find out what ports a particular PC can
access on our server?

I'm trying to set up a bloke's home PC over the phone - not an easy task
when the guy doesn't know a hell of a lot about computers! Anyway, I just
want to check that his PC can actually access the port number it needs to.
(If it helps... the server is currently listening on this port.) The real
kicker is, I don't know whether the application we're trying to set up want
UDP or TCP.

Any ideas?
Thanks.

PS. The remote PC is connected to a fileshare on our server. (I have no idea
what port number that is!)

 

[Lanwench [MVP - Exchange]]

What OS? Why not look into remote desktop or netmeeting? Re his access to
your server - you need VPN or something to do that, not just simple access
across the Internet. You need a firewall to block all dangerous and unneeded
inbound traffic...

 

[Invisible]

What OS? Why not look into remote desktop or netmeeting? Re his access to

your server - you need VPN or something to do that, not just simple access
across the Internet. You need a firewall to block all dangerous and unneeded
inbound traffic...

Sorry - did I not say that? We have a VPN... otherwise our firewall would
block any attempt to connect to our fileserver.

His OS is Windows 2000 Professional.
Our server is Windows NT4 Server.

 

[Lanwench [MVP - Exchange]]

Through VPN, what can't he do, then?

Sorry - did I not say that? We have a VPN... otherwise our firewall
would block any attempt to connect to our fileserver.

His OS is Windows 2000 Professional.
Our server is Windows NT4 Server.

 

[Invisible]

Through VPN, what can't he do, then?

It *appears* that he can't access port 3698 on our server. (Like I said,
don't know if that's TCP or UPD.) Basically this screwy application software
uses that port by default, and it seems the copy running on this bloke's
remote PC can't auto-detect our server. (Annoyingly you can't specify the
server name manually either; you MUST use that auto-detect.) However... the
port is adjustable...

I just wanted to check whether port 3698 on our server is actually
inaccessible from this remote PC, or whether the problem is something else.
(Hard to tell - the application software is so dam finiky :S)

Thanks.

 

[Invisible]

Look here for a list of the commonly known ports.

Hopefully, that'll pin down what port you're trying to use.

http://www.good-stuff.co.uk/useful/portfull.php

Thanks for that. We're actually trying to set up an application program that
uses its own custom protocol on port 3698 (don't know if that's TCP or UDP).
Out of interest... are TCP port numbers and UDP port numbers actually
seperate? Various technical sources *imply* they are, but none explicitly
*say* so...

Then, if there's a web server like IIS that's unused on
that server, configure it to use that port unstead of #80
and get your bloke to point his browser at the <IP address
of the server>:<port #> and see if he gets an http default
page back !

Hey... that would work! (Well, have to stop the application listening on
that port first ;-) But yeah... wouldn't wanna touch IIS - we shouldn't even
be running it but we are! I could use something else tho... anything that
can be reconfigured to listen on an arbitrary port... (oh, and that the guy
has a client for!) Should have thought of that myself...

Thanks.

(PS. Does NT have a telnet *server* in it somewhere? I know there's a
client... Can you put that on an arbitrary port number?)

 

[Lanwench [MVP - Exchange]]

Can he telnet to your server on that port? Just a thought...