PPTP VPN

[Guest]

Hello there,

I have win2000 server (SP4 and all updates via windows update) with RRAS
enabled (PPTP) one NIC. I am able to connect ok and all network resources are
available. The server has 10 WAN Miniport (PPTP) configured.

The server also has 11 static address in its pool of addresses which I know
gets assigned to VPN clients.

Initially, the problem I was having, were packets being dropped, the client
VPN connection stays active but the user was unable to access any resource,
icmp packets would also drop out. With further investigation, I now found out
by accident really that when there is only one VPN connection, everything
works fine but as soon as I have another user establish a VPN connection,
both connections stay active but they are both unable get to any resource.

From the RRAS Console I can see the active connection and IP addresses
assigned (no conflicts) but all packets are dropped.

Please help as this is driving me absolutely up the wall.............

 

[Robert L [MS-MVP]]

I will check the MTU first. these links may help,
VPN slow issues In a case you may need to modify the MTU size and wonder how to determine the optimal MTU for your system. ... www.howtonetworking.com/VPN/mtu4.htm ...
www.chicagotech.net/vpnslow.htm


VPN connection is disconnected after serveral minutes VPN drops the connection. VPN is very slow. To change the MTU Settings, select the the following ... How to modify the MTU Settings for VPN Connections ... ...
www.chicagotech.net/VPN/vpn3minutes.htm


Can't access RDC over VPN I would check the MTU first. Or check this link: vpn drop connection ... Then he can use RDC over VPN. Related Topics. How to change MTU ... ...
www.chicagotech.net/Q&A/vpn47.htm


vpn drop connection You can copy a small file between two offices but it may drop the VPN connection when ... Resolution: modify the MTU. Related Topics. How to modify the MTU ...
www.chicagotech.net/vpnissues/vpndorp1.htm



Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
Hello there,

I have win2000 server (SP4 and all updates via windows update) with RRAS
enabled (PPTP) one NIC. I am able to connect ok and all network resources are
available. The server has 10 WAN Miniport (PPTP) configured.

The server also has 11 static address in its pool of addresses which I know
gets assigned to VPN clients.

Initially, the problem I was having, were packets being dropped, the client
VPN connection stays active but the user was unable to access any resource,
icmp packets would also drop out. With further investigation, I now found out
by accident really that when there is only one VPN connection, everything
works fine but as soon as I have another user establish a VPN connection,
both connections stay active but they are both unable get to any resource.

From the RRAS Console I can see the active connection and IP addresses
assigned (no conflicts) but all packets are dropped.

Please help as this is driving me absolutely up the wall.............

 

[Guest]

Thanks for the quick response

Having read the articles, I am still unsure how this relates to my issue of
concurrent connection dropping packets; remember they are not being
disconnected.

Also my users use a variety of connections methods onto the internet
(dial-up, dsl & adsl). I also failed to mention that I have had multiple
users on the VPN in the past without any problems. I am unable to say exactly
when this issue began.

The server has not been modified, bar windows update. I created Temp-RAS
server (using the Wizard) just to rule out the other server and had the same
issue.

anthony

 

[Guest]

Hi

I finally found what the problem was to this issue, my external firewall was
natting the traffic onto the PPTP server, and doing so with the source IP
address hidden, unhidding this resolved my concurrent connection.

Using network monitor while having one user and then two users showed that
the source ip address was being transferred to the newer connection hence the
loss of connectivity for the first user.