Something has been happening on my company's network at 9:30 every day. I'm not the sysadmin but he's not a ServerFault guy so I'm not privy to every aspect of the network but I can ask questions if follow up is needed.
The symptoms are the following :
- Sluggish network and download speed (I don't notice it, but others do)
- 3Com phones start ringing without having people on the other end.
We've got the following ports exposed to the public for a web server, a few other ports for communicating with our clients for tech support and a VPN. We've got a Cisco ASA blocking everything else. We've got a smallish network (less than 50 computers/vms on at any time). An Active Directory server and a few VM servers. We host our own mail server too.
I'm thinking the problem is internal, but what's a good way to figure out where it's coming from?