PBM: VPN packets dropped after 1 min. with pptpd/pptpclient

[VinzC]

Hi.

I have setup a Gentoo Linux VPN server (of course) with the following components:

• net-dialup/ppp-2.4.2-r15
  
• net-dialup/pptpd-1.2.3-r1

The VPN server accepts connection requests from Windows and Linux machines. The VPN server is behind a 3Com firewall/Wifi router on which I have forwared port 1723 towards the VPN server (there is no distinction between TCP and UDP on the router).

On my laptop I have installed Gentoo with the following components:

• net-dialup/ppp-2.4.2-r15
  
• net-dialup/pptpclient-1.7.1

I can establish a connection and ping the remote server. But after exactly one minute the link doesn't seem to work anymore. Ping seems to send packets but they don't get back - I can gather from the send/receive leds on my cable modem. In short my VPN connection remains but packets are dropped.

Most of all I can make successful, stable connections from Windows and they do remain. I usually have no problem in making VPN connections to other VPN servers from the same location, be it under Windows or Linux. This is frustrating!

I have run pon with debug arguments and tried tcpdump on both sides but saw nothing wrong. On the server's side packets don't seem to come in: tcpdump stops dumping lines while my laptop (the client) continues sending echo requests.

I suspect the 3Com router has something to do with the link but cannot figure out how to debug and find out what exactly goes wrong.

Any help would be appreciated. Thanks in advance.
_________________
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1739!

[BonesToo]

I have a similar problem. I'm not running the vpn server, my work does. But I am able to connect to my works vpn on windows using cisco vpnclient 4.6, and until the other day when I bought a new Linksys router I was also able to connect to the vpn from linux, also running cisco vpnclient 4.6.

But ever since I got the new router, I can establish a vpn connection in linux, make a few requests, and then something starts dropping packets. If I ping a computer on the vpn network, the pings work 10, 20 , maybe 30 times, but after that I don't get any response. Something starts dropping the packets.

Does anyone have info on how to debug this? What net tools I can use to see where in my network, client or router, the packets are dropping? I REALLY don't want to boot windows to connect to the vpn. I want to use gentoo for everything

Thanks