Hello all I have an issue with my SG300-28P switch. I am replacing a previous switch of the same type, I can plug in both Fiber gigabit ports and all the network and VOIP phones work just fine. I can then plug in one port connection and they still work fine, but the moment that I add 2 or more connections to the switch it drops the network from the VOIP phones and PC's. Oddly the phones stay lit up and on but no dial tone comes through.
Network is Windows 2008R2
Phones are Panasonic KX-NT343