At my workplace, we are given access to the main corporate network via network ports at our desks, that are connected back to Cisco switches. I do not know the model etc, only that they are Cisco switches, and I don't have any level of access to them.
Separate from the corporate network, In my department, we have a few HP ProCurve 2510-48G switches and a couple Cisco 2960G switches that are trunked together.
When I connect from my corporate network port to any unmanaged (dumb) switch, the corporate Cisco detects it and shuts down the port. I have to then call tech support to get them to re-activate it.
If I connect the corporate connection to the Cisco 2960G switch, the port shuts down (again).
However, when I connect the corporate network port to the HP ProCurve, the port does NOT shut off!
The corporate port stays alive and happy as long as the (HP) VLAN that it is on is not trunked to a Cisco. In other words, even if the VLAN (call it 99) is trunked across all of my HP switches, the corporate port will stay active. The moment I configure that VLAN to trunk over to the Cisco as well, the corporate port goes down.
Now, there's something about the HP ProCurve which is preventing the corporate network switch from detecting the HP as a switch. How can I find out what it is and get my Cisco 2960G to mimic that behavior, so that when I connect or trunk to it, the corporate network port stays alive?
Thanks in advance!