I manage an office of about 100~ people, with an old Server 2003 R2 box which is pretty much everything - DC, File Server, DHCP server, etc. All our network shares come from this server.
I also have a Cisco Aironet 1250 WAP which provides wireless to about 30-40 laptops and wireless devices.
A couple months ago, I created a separate VLAN (192.168.0.0 is our main; 192.168.100.0 is VLAN 100) for the wireless clients. Everything seemed fine - the SSID is set to connect to VLAN 100 and the trunk ports are all configured correctly, at least theoretically.
However, ever since then, I've been getting complaints that the network shares over wireless are highly unstable. While browsing for files, or saving already-opened documents, the folders being accessed come back as blank and the error message:
An error occurred when reconnecting R: to:
Microsoft Windows Network: The local device name is already in use.
This connection has not been restored.
The users access these shares over mapped network drives. However, accessing the File server directly by UNC also proves unstable.
I've done quite a bit of research and snooping around to weed out the root of the problem. Granted the Aironet 1250 is more complex to set up than what my abilities allow, nothing has really changed besides the IP address of the device and the VLAN the SSID connects to.
Also, the wireless connection itself does not appear to drop when these messages appear - pinging the server is completely fine with no hiccups, and Internet access is fine as well. Link quality is also fair - three and four bars as measured by Windows, around 60-70 dB being measured by inSSIDer 2.0.
Any ideas on how to correct this problem would be appreciated. Any pointers on where else to look also. Thank you.
Yes, NAT is enabled between VLAN 0 and VLAN 100. Both are managed by the same router, however, a Fortigate C60. Firewalls exist but all traffic between the two subnetworks is allowed. Nothing on the software side.