I plugged in the GLKVM Comet to the same (unmanaged) network switch as my wired PC. I can PING it no problem. When I plug in the GLKVM Comet to a different (unmanaged) network switch, which is connected to the same LAN, I cannot PING from my wired PC. However, I can PING it from a wireless computer on the same local network.
If I plug the GLKVM Comet to an available port on my router, connected to the same local network, I can PING it.
I only have one subnet (192.168.1.0/24). I have no issues PINGing any other device connected to any wired switch on my local network.
Our testing department informed me that they haven't encountered such an issue. Could you provide the model number of the problematic switch? We can purchase it to investigate further.