I came into this setup and there is a HP and a Cisco switch connected together. Connected to the Cisco switch is a VoIP phone and a computer is connected to the VoIP phone. There are no issues with the phones being assigned properly, just the computers. The HP switch is configured so VLAN 1 allows for the data traffic and VLAN 20 is for the phone traffic. The Cisco switch has VLAN 20 for the phone traffic, but it looks like VLAN 10 is for the data traffic. The default VLAN is 1 but no ports except the trunk port has been assigned it. The computers that hook into ports with VLAN 10,20 assigned are assigned onto the proper network. If I plug the cable into a port assigned just VLAN 20, then it doesn't get assigned on the proper network. How can the HP switch use VLAN 1 and the Cisco switch uses VLAN 10 and it still works?