Topic: Flaky PPTP - bug?

[EB]

Hi,

I've been following a discussion on the devinfo mailing list regarding PPTP. I have an e-smith 4.1.2 at home and at work. I have been trying to get pptp working for like a month now. I have never been able to connect. I recently started monitoring the pptp port (1723) on both servers. I finally found out why I can't connect. The pptp port keeps disappearing and reappearing on both servers. I'm using win2k pptp client by the way. When I scan the server and the pptp port is open, I can connect and everything works great. The port disappears randomly. Now I'm trying to figure out why this works all of a sudden. I have changed NOTHING on both servers. It just started working/not working. I have zonealarm installed on my work pc, and another firewall on my home pc. I disable them when using pptp, so there should be no interference from them. The other strange thing that happens is that there is a message repeatedly displayed on the e-smith console:

"No free connection slots or IPs available - no more clients can connect!"

 It is displayed over top of the console text, and wraps around the screen over and over. Could my ports be disappearing because somebody/something is trying to connect continuously? Or is there a problem in e-smith, or Win2K? Doesn't quiet make sense to me. If anyone has any suggestions, I'm listening. thanks,

EB

[EB]

Hi there,

I did some more investigating, and maybe some people would be interested in the results. Charlie Brady mentioned that ZoneAlarm could be causing problems. So in order to find out if that's what was causing the ports to open and close I played a little bit. I scanned the pptp port in 2 different ways. One way is with a little port scanning utility from my workstation. The 2nd way is from www.sdesign.com so that I would have an external source to compare to. Now I found something interesting. While ZoneAlarm was running, you can scan the pptp port on the remote computer and it shows up on the port scan (from the local workstation). When you try to connect to the remote computer, ZoneAlarm blocks any attempts. Ok. Makes some sense. Now, when you disable ZoneAlarm completely, funny stuff happens. When you shutdown ZoneAlarm and scan the pptp port from your workstation, it appears only for a minute. After that, the pptp port completely disappears, even though you were able to see it while ZoneAlarm was running. www.sdesign.com confirmed that the pptp port was still visible. It looks like there is some networking issue in Win2k/ZoneAlarm that does something wierd here. So I removed ZoneAlarm from my system completely, and the port is always visible and I havn't had any more problems. I don't quite understand why you have to remove it from your system. Maybe I had to disable it and reboot. i don't know. I use Network Associates eTrust firewall now, and everything works great. I hope that helps someone who has had similar problems.

EB

[Charlie Brady]

EB wrote:

> The other strange thing that
> happens is that there is a message repeatedly displayed on
> the e-smith console:
>
> "No free connection slots or IPs available - no more clients
> can connect!"
>
>  It is displayed over top of the console text, and wraps
> around the screen over and over. Could my ports be
> disappearing because somebody/something is trying to connect
> continuously?

Or is already connected. How many IP addresses do you have allocated for pptp connections? The PPTP daemon will stop listening for more connections when it has no more IP addresses that it can allocate.

Charlie

[Prab Gill]

Hi Charlie,

Where do we allocate ip addresses for PPTP? All I know is go to REMOTE  ACCESS configuration screen under E-smith manager and select number of PPTP clients. I have already selected 2 but it still does not work. I will appreciate your help.

Regards,

Prabhjot Gill