Dopped connections for VPN

[rlcolvert]

Good morning
We are using Sprint DSL to establish VPN connections from our remote office to headquarters.
Clients are both Win98 and W2k, using PPTP through microsofts native VPN client to a Cisco 515 PIX.
Each client creates their own session and proceeds to work using corporate resources.
The problem is that sporadically throughout the day one client or another will drop their VPN connection.

From the PIX side there appear to be no errors and traffic over the connections is not high enough to cause delays.

Any suggestions on what may be happening?

Thanks
Richard

 

[John Lewis]

First place I would look: Make sure your clients have 'Negotiate multi-link for single link connections' disabled. (Properties for the VPN connection, Networking --> Settings).

Caution! Registry stuff here, if you don't know what you are doing with it, leave it alone. Having said that . . .

W2K SR2 does not have this option on the properties form, and it is enabled by default. You have to edit the registry to turn it off. Check to see if it is on the properties page first. If it is, change it there and leave the registry alone. The key is here:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RASMAN\PPP
Add value:
Value Name: DontNegotiateMultilinkOnSingleLinks
Data Type: REG_DWORD
Value: 1

Beyond that, keep in mind that your connections are going across the public internet. You can see adverse effects from heavy internet traffic in general or localized near your client or server or anywhere between. Occasional drops are to be expected, more frequent, you might want to have your userers do a tracert to your server dumped to a file immediately after a dropped connection so you can see if there is a consistent problem somewhere.