I don't know if this is the correct forum for my question. If it is not, please move the question to the appropriate location.
We have an intermittent problem that started (approximately) when we installed a VPN between our 2 offices.
Office 1 has an XP server, and 5 PCs with win XP, 2000 and 98. Office 2 has 2 Win XP PCs. The connection between the 2 uses Netgear FVS318 firewall/routers and D-Link 302G ADSL modems.
A day or so before the change to VPN 1 PC crashed several times, including blue-screen-of-death messages. The real problem started somewhat later, after the installation of the VPN. The network connections within office 1 have become extremely intermittent. Office 2 is largely unaffected.
Sometimes the entire network disappears for one or more PCs, and somewhat later, without making any changes, it reappears again. At other times individual PCs disappear from the network.
Her is an example. One PC shares its disk with another. This share disappeared. In order to keep working, the user set up a new share for just the folder that was required. This share was visible for an hour or so, when it too disappeared. While we were scratching our heads, the entire disk suddenly became shared again.
At other times people will use all or part of the internet connection. For example, while able to receive and send email, web browsing may be impossible. Sometimes just the link between the 2 offices disappears while the local network stays up (i.e. only the local network is visible in My Network Places), at other times the reverse happens.
At the same time, the office 2 people have no problems with their internal network, nor with internet access. To them the office 1 network is also always visible, although the connection can become very slow.
Our virus software is fully up-to-date (it even catches Mydoom) and most PCs as well as the server have been scanned. We have tried unplugging the router but that made no change at all. At one stage we unplugged 3 IP printers, and found that the network came up immediately, but only for half an hour or so. We tried changing IP settings on the PCs and server, to no avail.
Any ideas that can help us resolve this problem will be most appreciated
