Testing ports with Telnet

[Gomjabber]

I work for a company that provides ISP, along with other services. We have a customer that is using security cameras. We have a dedicated 1.5 connection to their equipment. The camera company can't access the cameras remotely and are insisting we are blocking the necessary ports. There are 3 needed: 2000, 37777, 37778.

All blocking has been removed, the circuit is completely wide open, yet they still say we are blocking ports. If I Telnet to the IP and 2000 or 37777, it replies as it should. 37778 always rejects the connection. My router doesn't reject packets, only drops them. So it seems the equipment has a problem, or is misconfigured, but I can't seem to get the camera guy to admit it.

He's basing his contention entirely on an online port scan, forget which program it is.

Anyway, I want to prove the ports are open and get the guy out of my life. What I wanted to do was configure a laptop as a Telnet server and plug his connection into it, directly in front of his equipment, Telnet to those ports and prove they are open. But getting Telnet working has proven frustrating, and I don't understand why its fighting me so much.

This is the setup I'm testing here in the office. The laptop acting as the server is running Vista. I went to Programs and features and checked off on Telnet server, then started the service from the services console. If I use my W7 computer (setup as Telnet client) I can get to a login on the remote computer (the Vista laptop) using (at a telnet prompt) open (IP ADDY) port (23). But if I try 2000, 37777, 37778, I get an error saying the connection couldnt be established.

If I use the exact same syntax to the cameras connection, I get the usual responses (2000, 37777 connection, 37778 rejection). I tried replacing the W7 client with Putty and get basically the same results. And on the Vista laptop I went in to the firewall and made exceptions for the three ports.

Is there a piece I'm missing? Any help would be appreciated.

 

[Sheepykins]

bump, I always have problems opening ports for W7 and Vista, have you tried turning off all firewall etc applications, silly thing to do i know but the interface for opening ports on the new windows firewalls is absolutely terrible.

Yeah online port scanners arnt always effective, i can name 10 off the top of my head that run from a browser with disclaimers saying "might not always work"
I dont have much networking experience though so you may be thinking "im not stupid Sheepy, gawd" but maybe your office network is the one stopping you also, can you i dunno... telnet to a home box just to check?

Also which versions of these Windows OSs are you using? im sure some of the more basic versions do not like remote access, or have limited capabilities when it comes to remove access, Vista home premium compared to business for example.

hope thats food for thought

 

[Gomjabber]

bump, I always have problems opening ports for W7 and Vista, have you tried turning off all firewall etc applications, silly thing to do i know but the interface for opening ports on the new windows firewalls is absolutely terrible.

Yeah online port scanners arnt always effective, i can name 10 off the top of my head that run from a browser with disclaimers saying "might not always work"
I dont have much networking experience though so you may be thinking "im not stupid Sheepy, gawd" but maybe your office network is the one stopping you also, can you i dunno... telnet to a home box just to check?

Also which versions of these Windows OSs are you using? im sure some of the more basic versions do not like remote access, or have limited capabilities when it comes to remove access, Vista home premium compared to business for example.

hope thats food for thought

Yo Sheepy thanks a lot for responding. Sorry for not getting back to you sooner.

I set up my bosses Vista machine as a Telnet server, my W7 as a client. When I tried to Telnet to 37777 it gave me an error saying only ports 1-1024 were usable. Arrrgh. So I took bosses comp down to where the customers' equipment is and had someone in my office Telnet to ports 1020-1022, which were open and accepted the login request.

Turned out to be a moot point however as the camera tech suddenly mentioned in an email he needed a router with port forwarding (up to this point, had been a wide open 1.5 connection from my edge router). Chaos ensued, but in the end we wound up installing a Lynksys black on blue and port forwarding to a private number behind the router. And it worked, so alls well that ends well.

Still, Telnet fought me unnecessarily. One thing you have to remember to do is on a Windows machine, go to the services console and make sure the telnet service is started. Dropping the SW firewall helps too. Why I was limited to ports below 1024, no idea.

Thanks again Sheepy.