Closing the PPTP Port Under Windows 2000?

phnork asks: "I have asked many skilled Win2K users and networking specialists how to close Port 1723 in my Win2K system. I have searched the net unsuccessfully, browsed news groups, asked my ISP techies, and even asked my wife. But, although all agree the port normally used for PPTP (VPN) should not be open, no one has taken the time to document how nor post the solution where it can be found. In fact, I have found that most security issues that abound in the Wide World of Windows occur because those in the know, do not. Not even Microsoft! If they did, the solution would be as easy and straight forward as setting up a printer. Networks and security are still relegated to the nether worlds of the 80s where we used to have problems with every printer installation and computers were hauled to a grinding stop by the inability of the protocol lords to arrive at a consensus. But, maybe now the solution is at hand. Now that I have asked for help maybe someone will come forward with those super words, 'Try this...'." What other hard-to-close ports have you found open in your Win2k install. What did you have to do to close them?

Comments

RRAS?

[Grizzletooth]

Are you running Routing and Remote Access Services on that machine? I don't see 1723 as a default open port on my servers that don't have RRAS enabled.

PPTP?!?

[Anonymous Coward]

Couldn't they think of a better name? That always sounded like a restroom on an Indian reservation to me...

Try TCPView from sysinternals

[Fat Cow]

That should tell you which process is listening on that port. Then you can stop the appropriate service or kill the appropriate process.

joke.. right?

[undef24]

This is a joke right?

Go download Active Ports and see what program is actually casuing that port to be open.

You can also try running this document in the reverse order to uninstall PPTP :)

Is this all the info you got?

[shyster]

I don't know what "skilled Win2K users and networking specialists" you've been talking to, but I think some more info may be in order here.

Though I don't have a Win2K machine handy to test right now, I don't believe it's normal for that port to be open for no reason. I can verify that neither my WinXP PC and my Win2003 server have it open, and I don't recall it ever being opened on Win2K.

Are you running Win2K Professional? Do you have the RRAS service running? Have you tried any diagnostic tools like TCPView to isolate the process? Up to date virus scan and adware scans? Any communication on that port? Any odd processes in TaskManager? If you shutdown background tasks, does that port remain open? Oh, and since you seem to be lacking in ability, how did you come to the conclusion that port was open?

..,no one has taken the time to document how nor post the solution where it can be found.

The solution is simple. Stop the process listening on that port. I don't think anyone needs to write a HOWTO on that. And seeing that I haven't heard of anyone else complaining about this (nor seen it myself), I'm inlcined to believe it's something unique to your setup - not Windows.

I have found that most security issues that abound in the Wide World of Windows occur because those in the know, do not.

Perhaps those that think they are "in the know, do not" (like ISP techs). But those of actually in the know do know how to track down a process holding a port open.

I think, phnork, that you may want to hold off on your anti-MS diatribe until you find what the issue actually is. Dollars to doughnuts it's your fault, not MS.

RPC Config

[Vlad_Drak]

By default RPC/135 listens on 0.0.0.0, but you can change this by using MS's rpccfg.exe to listen on the loopback only.

http://www.microsoft.com/windows2000/techinfo/re sk it/tools/new/rpccfg-o.asp

Also, port 445 is open, even if you disable File and Print Sharing. To fix that hole, open up regedit and change:

HKLM\System\CurrentControlSet\Services\NetBT\Par am eters\TransportBindName from '\Device\' to nothing. You can't use the workstation service|CIFS outbound either when you do this though, and you have to reboot for it to take should you want to switch back.

I've never had a problem with PPTP or the port you mentioned, maybe try disabling Routing and Remote Access, or other services.

I have my Win2k3 box only listening on 22, OpenSSHd and scp work like a champ.

Michael Johnson took over the NetworkSimplicity OpenSSH installer, which makes it too easy not to use SSH on Windows.

http://lexa.mckenna.edu/sshwindows/

-Vlad

Re:Good luck

[zero_offset]

That's probably the dumbest way to find an answer up there. If he truly ran around on campus all day, that explains why he didn't get anywhere. The MS campus is physically huge, there are thousands of people there, and that doesn't include their satellite offices in Bellview and other surrounding areas. Running from building to building (which would eat up a significant portion of your day, in itself) is about the least effective way I can imagine to try to find anybody there.

We occasionally need heavy-duty tech support (for example, a couple years ago we identified an obscure but severe bug in COM), and I can usually hook up with the right person with only two or three e-mails and a few hours of waiting. All unofficial, and all back-channel, but not terribly difficult. And most of those addresses I've culled from public articles over the years. Only a few were given to me in person as a "here's my address, keep it to yourself" kind of thing. I've found that even if you contact the wrong person up there, if the request is serious, well-written (e.g. not "d00d, cn U help me? thx"), and appears to be reasonably outside the capabilities of their usual support services, they'll go out of their way to try to put you in touch with the right person. Not only have I always reached somebody who was quite knowledgable, but very often I reach the person who wrote (or currently maintains) the code in question.

And frankly, I'd be surprised if a staff MSJ writer didn't have those kinds of contacts.