I've been experiencing a frustrating issue recently where certain VPN users can't access mapped drives or browse file shares on our file server while connected through a Sophos SSLVPN. They can ping the domain controller and file server without any problems, yet they receive timeout errors when trying to load files. Strangely, other users can access the same resources without any issues, leading me to believe it's not a network-wide problem. The network setup is relatively straightforward: we have a Hyper-V host with a DC VM, FS VM, and RDS VM, all connected through a single subnet with a Sophos firewall. Rebooting the file server VM temporarily solves the issue, but I'm seeking a permanent fix. I've checked event logs, disconnected open sessions, and made sure everything is configured correctly, but I'm at a loss for the root cause. Any insights or suggestions would be appreciated!
2 Answers
You might want to reset the network stack on the file server, as it can occasionally become corrupted. Also, check if any antivirus software is interfering. Always using fully qualified domain names can help to avoid issues with DNS suffixes or falling back to NTLM, too.
Have you considered the possibility of a duplicate IP address? It might be rare on a small network, but it could cause some of those connectivity issues when VPN users try to access the file server.
No, I've ruled that out. The firewall has IP conflict monitoring enabled, and the file server has a static IP.
Those are good suggestions. I've disabled the AV in the past without issues, and I'm also using fully qualified names for everything. I've just reset the network stack, but it’s a tricky problem to reproduce, so it'll be hard to test for effectiveness.