Windows Forum

Ask something
Discussion Locked

VPN and time out issues

0 helpful
10 replies

by todd 2 views

Closed to new repliesThis discussion is closed. It stays readable, but it takes no new replies.

I have setup a VPN, using NT, and RAS. I am trying to connect from a remote location. My user name and password get verified, but I get a time out error when trying to register my computer on the network. The TCP/IP never gets negotiated. If I enable NETbuei also, that WILL get negotiated with a message the the TCP/IP didn't
Any ideas? anyone?
I tried server assigned IP,s and also specifying one on the dialup side (with this option permitted in the ras server) I have 10 IP's assigned to the VPN pool and only 4 ports. so running out of IP's is not the issue.

10 replies

by vn

Before you can resolve this issue... you MUST remember that 95 / 98 can ONLY hold 5 ADAPTERS in Network Neighborhood. If you have AOL installed...forget it.
IF BOTH machines can surf the web....your TCP/IP protocol is functioning. (If NT fails tosurf...make sure you disable the VPN FILTER)
Once both machines pass and your 95/98 machine has dial-up and VNP's installed... make sure that your SECURITY is set... ie. encrypted password required - 40 bit to 128 bit on BOTH ENDS !!!! ALL VPN is done with TCP/IP and since you are able to log in...your TCP/IP is working... YOUR 95/98 VPN adapter is NOT with the TCP/IP. If worse comes to worse...reinstall VPN on the 95/98 box. All this should point you to the right door.

by especkma

As I recall, this behavior occurs when one of the routers between you and the PPTP server is filtering one of the packet types that PPTP requires. I am sure a search of the MS knowledgebase contains more information.

The basic issue is that PPTPuses an IP protocol or service that is also used for transmitting routing information within networks. Some organizations filter this packet as a security measure.

I beleive there are utilities, perhaps part of a service pack, or a revision to the WInNT resource kit that can be used to confirm this diagnosis.

Sorry I couldn't remeber the specifics, but this should point you in the right direction.

by originalskinnyj

The part that could be getting filtered out is the GRE header, a standard part of PPTP, contact your isp to see if they have GRE filters on their routers.

by todd

Further test results:
Still having trouble. The machine I am using and attempting to connect with is NT Workstation. I have tested the VPN server with another NT server, at a different location and was able to connect at without a problem. This tells me I have the firewall that is located on the lan where the VPN server is configured correctly. Still looking for other suggestions.

by jessed

Tood, does your PPTP server have only one NIC? If it does, RAS will create problematic default routes, that will prohibit IP packets from routing properly. Microsoft does indeed have some good KB articles (Q171922, Q176321, the latter probably beingyour best place to start). Of course, NetBEUI will work fine because it's completely NetBIOS based without any IP.
-jd

by todd

All IP traffic other than PPTP is routing properly.

Final solution was to remove all Network components from the NT Workstation and reinstall TCP/IP, RAS, and PPTP.

This discussion is closed to new replies.