We have had an annoying situation where occasionally, at about 8:30AM, when people start arriving to work at one of our client's locations, their network will go wonky.
They have 4 servers that will randomly be reachable via RDP (they all reside on different ports like 3390, 3391, 3392, 3393, etc, behind a firewall).
One minute, we can reach one and three fail, the next, we can reach two others, but not the original one.
It's also affecting a remote site that uses MPLS between the two locations.
The firewall is an ASA5505 and appears to be functioning normally. We have replaced it, just to see if it was indeed the problem. Nothing has changed in the config, it has worked perfectly for 2 years.
From inside, all resources can be reached.
The wireless network consists of 3 cisco APs, which 25 mobile devices, from Android to iPhone to iPad and notebooks will connect to in order to get to the Exchange server.
After we disconnected the entire wireless network, everything seems to work okay.
My thoughts are, a phone is coming in, and binding to a router IP address...
Routers are:
192.168.1.2 Windstream router for MPLS and internet outbound
192.168.1.252 Router to another LAN
192.168.1.254 Cisco ASA 5505
Rebooting our Cisco doesn't always fix the issue, but rebooting the 192.168.1.252 Windstream router does. Windstream has replaced their router too.
I realize the local subnet of 192.168.1.x is the same as many home networks and wireless hotspots that people might be on, but there is no changing that for them, they have too many static devices and routes.
Any ideas for how we could insure a wireless device doesn't come in and bind onto an IP, other than moving them off to their own subnets (we still need to get them to the 192.168.1.251 Exchange server).
Thanks!