Creates tunnel VPN but cannot Ping

[wmin]

Has anyone experienced a scenario where VPN client established a successful connection to a remote network yet could not ping any resource.

I get a successful log every time and I can see active VPN connection on a remote Firewall. Occasionally it changes it's mind and it pings remote hosts, I can even launch a remote desktop, but does not work again at next connection.

This VPN has been working for a fine but we had recently changed service provider and a modem to take advantage of high speeds. This broke everything.

Equipment that we use is netgear FR318 for firewall and DM602 for a modem. Both have latest firmware installed.

DM602 is in a modem mode with DMZ pointing to FR318. DM602 and FR318 WAN IP address is in a different range to LAN (eg 192.168.0.x for LAN and 192.168.5.x for WAN).

I have burned days screwing with this thing. Is there any poor souls that know the answer?

 

[msworld]

It could be the TCP/IP settings issue. Do you use IPSec or PPTP. Posting the result of ipconfig /all here may help.

Bob Lin, MS-MVP, MCSE & CNE
How to Setup Windows, Network, VPN & Remote Access on

http://www.HowToNetworking.com

 

[wmin]

Hi Bob, As far as the firewall is concerned and router on the other end, all required ports are open. It all worked fine until we replaced a modem on VPN Server side. In fact, when I switch back to old modem on old DSL connection it works fine again. This makes me certain that VPN Server and Client configuration is correct. Everything points to either Bulldog or DM602 - which possibly does not forward ports properly, even though i opened DMZ on DM602 (which points to FR318).

Netgear suggested that there may be a problem with MTU setting and advised me to lower it - it did not work.

Any other suggestions?

wmin

 

[Lote]

Just to check have you updates all the DNS and gateway settings?

 

[wmin]

Lote, all settings have been checked, rechecked and then checked again. I would imagine that if there was somekind of an error, it would a) not establish a VPN connection at all and b) on random occasions would not ping or open remote desktop.

What do you think?

 

[PeterHurst]

You say it works fine back on the old connection but occasionally on the new - That would suggest to me a routing/gateway issue with the firewall.

Is the firewall still configured with some manual settings poining at the old ISP?? Statis routes or NAT exemtion lists?

 

[wmin]

Peter, in order for it work with the old ISP, of course, I have to modify Firewall's WAN ip and client's Gateway IP addresses. There are no nat exemption lists or stat routes.

 

[JOAMON]

When not able to ping, did you do a traceroute to see where it is failing? Need to know how far it can get to determine which device to work on.