Outlook problem over VPN

Hi All,

I have a problem with access to Exchange server on outlook for users who are connected via VPN connections.

Firstly, a little background;

I'm currently running a Server 2003 domain. Primary domain controller is a server 2003 machine, and the Secondary DC is an old win2000 machine. Exchange 2003 is installed on primary domain controller server, along with our BES server and spam filter.

Clients connect to the VPN in one of two ways. Either they connect via the Windows Routing and Remote access VPN connection, which is configured to hand out IP addresses from our DHCP pool. The RRAS server is currently on a windows 2008 server R2 (64 bit) virtual machine that is hosted on Microsoft Hyper-V - Its using the PPTP protocol.

The other method of connection is using our old Cisco PIX - I'm unsure as to the details of its setup as it wasn't myself who configured it.

Now, the problem. Users are able to connect to either VPN fine (with a couple of exceptions, however, thats a different issue) When connected they are able to browse the network, access files, use our CRM suite and access our fault tracking database as they would if they were sat at their desk in the office. And also most users are able to connect fine to exchange in outlook most of the time.

However, intermittently, and for some users more more frequently than others. Outlook just won't connect to exchange. They get the 'connecting to Microsoft Exchange' information in the bottom right corner, and then after a short amount of time, the status changes to 'Disconnected' I've checked and they are indeed able to ping the exchange server, they are able to access shared folders on that server also, but for whatever reason are unable to connect to Exchange. They are, however, able to access their emails via Outlook Web Access!

Sometimes, a restart of the exchange server is able to temporarily cure the problem, sometimes it isn't. One particular user claims he can only get connected to exchange during 'quiet' hours (Usually before 8am and after 5.30pm when everyone has left the office) The problem seems to mainly affect users connecting via the Microsoft VPN, however, I've seen the problem on users who use the Cisco VPN also. In fact there was one user who tried both and it didn't work on either!!

If anyone has any ideas that I could try I'd very much appreciate it. I've tried everything in my knowledge to sort it out and can't really think of anything!!

Many thanks in advance for your help! :smile:

James.