Remote (VPN) clients can not authenticate or use server resources

Posted on 2006-05-16
Last Modified: 2010-03-18
Problem: Clients in one remote location, connecting over HW VPN to the home office, are able to ping and browse network resources but anything that requires authentication fails. These clients are also experiencing very slow (10-15 minute) log on times. The VPN tunnel itself appears to be working correctly. An accounting application that communicates purely over TCP/IP works perfectly but anything that requires authentication (exchange, browsing shares, add/remove from domain, etc.) fails.

Environment: There are two clients in the remote location. They are both Windows XP SP1 and connect to the home office via a Netopia 4351 router. The router on the other end is also a Netopia. There is one other remote location that is *not* experiencing this issue.

What changed? : This setup had been working fine for 2 years. At the end of last week they moved in to a new building and switched ISPs from Covad to Qwest. The only thing that changed on the router (as far as I can tell) is the WAN IP address.
Question by:rrimar
    LVL 12

    Expert Comment

    Are there any errors in the event logs of the remote clients?
    LVL 12

    Accepted Solution

    This can be either DNS related or an MTU issue. I had a similar issue with a PIX to PIX VPN and it was an MTU issue. Once I adjusted the MTUs down to 1500 it worked great. Your ISP has changed and as a result you are on a different network, therefore it may very well be MTUs or DNS.

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