HF C/S port 4900 regected

Hi All,

Anyone know why port 4900 would suddenly be rejected? We have a school network that the client machines are getting a connection error. The connection error says "actively refused by the target machine". This is a small network of four machines.

Thanks,
Jeff

Hi Jeff...

I'm guessing here: Windows Update? Some of those have a tendency to mess up with settings...

best regards

Hi Fabrice,

We suspected that and anti-virus software (in this case, AVG). We are able to move the HF CS to another machine and connection works. We removed AVG from the original server and it still does not connect.

Thanks,
Jeff

Hi Jeff,

Typically an antivirus will not block ports, however, if that antivirus is bundled with a firewall then it is possible.

To get a better handle on what is happening, if this is an xp machine, open up a command prompt and type in the following;

c:\>telnet <ip_of_HF_server> 4900 [enter]

of course replace the <ip....> stuff with the real ip address.

If it makes a connection the entire screen should turn black with just a cursor blinking. If it doesn't you should get some kind of error. If the error is something like "unable to connect to ..." then my guess is that their is still a firewall issue on that PC.

If you do get a black screen that eventually drops back to a dos prompt, then something else is going on. You may need to install something like "Wireshark" to do some packet sniffing to see the raw TCP traffic for messages.

Hope this helps.


Cheers!
Ken

Hi Ken,

We did try the telnet and it would not connect. We used a program call TCPView on the server and it said HF CS was listening on port 4900. In the end the school is going to put a different machine as the server.

They were able to process lunch using a line machine as the server. Connie just installed the HF CS there and moved their data using LogMeIn rescue. It is impressive that you can install HF CS in just a matter of minutes remotely and the four networked machines just required an ini file change.

Thanks,
Jeff

Hi Jeff,

Glad to hear you got it up and running. One quick note; I typically try to do the tcp view stuff on the client that won't connect. 99% of all the cases I deal with where a particular computer will not connect, it is always some firewall problem. We've even had customers call up and say I was connecting fine before lunch and now it won't connect, just to find out that their norton / mcafee "security suite" received an update during lunch and starting blocking that type of connection.

Cheers!
ken

Hi Ken,

Thanks for the pointer. The computer that was not able to connect is where we moved the HF CS temporarily so I don't think the port was blocked on the client. They replaced the original server computer and moved HF CS back. All is well now. We have not heard if they identified a problem with computer that was replaced.

Will let you know if we learn anything interesting.

Thanks,
Jeff