A weird one...

I've got one of those weird ones today. We've installed a new network infrastructure - all shiny new HP Procurve stuff. Yesterday morning, one of our servers didn't back up, with BackupExec reporting that it couldn't see it. RDP'd to the server fine, and I could ping the backup server, and ping the errant server from the backup server. I could also, from either server, open an UNC share on ANOTHER server but not on each other. They're both on the same subnet, plugged directly into the new core switch, the ports on which are effectively, at the moment, wide open.

This morning, another server had the same problem, despite backing up yesterday. The error logs on the servers which can't connect have the odd DCOM error which, on closer investigation, could mean one of about forty different things, none of which look like an easy fix. It's all too easy to go off on some wild goose chase here. The core switch is new, so there's a cloud hanging over that, but I had something similar before it was replaced, which I didn't investigate too deeply as it was only a day before the new switch went in. One things for sure - something out there is screwing up my NetBIOS traffic, and I want to know what it is.