Open Port

DieHard

I have just done one of those online firewall tests and it says that port 21 is open. Does anyone know how I can close this port? Is there any setting in xp that can be switched off to close this port? This port has only opened up since I switched to broadband so I think it has something to do with that. Has anyone else noticed this when they switched to broadband and if they have how did they fix it?

JonnyF_2

IIRC Port 21 is usually FTP. This would suggest you're running an FTP server on your computer?

If you're running SP2, set the firewall to on, and "don't allow any exceptions" (in the settings->Control Panel->Security area).

If you're already running the SP2 firewall, try downloading the free version of Zone Alarm (https://www.zonelabs.com).

Hope that helps,

Jonny

DieHard

JonnyF wrote:

IIRC Port 21 is usually FTP. This would suggest you're running an FTP server on your computer?

If you're running SP2, set the firewall to on, and "don't allow any exceptions" (in the settings->Control Panel->Security area).

If you're already running the SP2 firewall, try downloading the free version of Zone Alarm (https://www.zonelabs.com).

Hope that helps,

Jonny

Thanks Jonny

I have done that and I have got Zone alarm and the port is still open, I am tearing my hair out, because I am not running an FTP server.

JonnyF_2

That's strange.

Have you used any FTP clients recently?
Try rebooting, that should close all ports, and they should only be opened again by the program which uses them!
Also, look which ports Zone Alarm is blocking, maybe port 21 is being let through.

Jonny

Toxteth_OGrady

To prove whether or not the port is open, open a Command Prompt and type in

Netstat

This will list all open ports on your PC.

:cool:

TOG

Alfie_E

Toxteth_OGrady wrote:

To prove whether or not the port is open, open a Command Prompt and type in

Netstat

This will list all open ports on your PC.

That will only show connections in progress, not listening ports. Use

netstat -a

to see all the open ports as well. It is important to realise that netstat shows ports that processes have requested be opened. They will show as open, even if a firewall is blocking any outside traffic from reaching them.

Important: Online firewall tests are often fatally flawed. They have a tendency to test the wrong computer. "Online test" tends to mean "web-based test", and they end up choosing the Internet address of the computer that directly connected to them. That usually isn't your computer, but your ISP's web proxy. The open FTP port is probably on that ISP computer. Even Symantec's online Security Scan gets it wrong for my computer connection. Do the following.

Start -> Settings -> Network Connections -> Right click on your connection's icon -> Status -> Support

The four numbers after "IP Address" show your computer's Internet address. (If you have a broadband router, look at the numbers after "Default Gateway".) If they don't match the ones shown by the online firewall test, the online test is testing the wrong computer.

Toxteth_OGrady

Good spot, thanks.

Actually netstat -b -v is probably a better bet. It'll list the processes using each port.

:cool:

TOG

wolfman

It's probably your router and not your computer. I'm not sure of your setup but I'd imagine that is the case. Some routers often comes with certain ports open, check the routers config.

wolfman

JonnyF wrote:

That's strange.

Have you used any FTP clients recently?
Try rebooting, that should close all ports, and they should only be opened again by the program which uses them!
Also, look which ports Zone Alarm is blocking, maybe port 21 is being let through.

Jonny

It won't be an ftp client, maybe an ftp server, but it's unlikely to be a client. Client ftp programs usually send an outgoing request on port 21, but the incoming response is usually on a much higher port.

DieHard

wolfman wrote:

It's probably your router and not your computer. I'm not sure of your setup but I'd imagine that is the case. Some routers often comes with certain ports open, check the routers config.

I have a safecom 4 port adsl router connected via the an ethernet connection.

How would I check the routers config?

wolfman

You'll need to log into the routers setup config. In most cases this is done via a browser window. Best check the manual see what it says.

Then once in, look for a section about port forwarding, or nat, or open ports etc... something along that kind of line.

If not it may be in the admin part of the router, ie my router has a way of connecting to the router itself by ftp and telnet etc... Your best bet would be to change this to a much higher port, like 21212.

It's difficult to be of much more help, consult your manual and it should detail how to open and close ports.