Thank you for the documentation. It turns out the item I was missing using the switchport mode general configs with the default pvid. Once I configured that, I was able to get traffic flowing.
My company has recently added a new floor and we purchased Dell N2048 switches. I'm new to this gear and have some questions relating to trunking and voice vlan configurations.   I've set the N2048s as a stack. The Dell switches have are directly connected to some older Cisco switches via fiber over 1G SFPs.   My Cisco switch has the following config on the trunk port Gi4/0/1: interface GigabitEthernet4/0/1switchport trunk encapsulation dot1qswitchport mode trunkspeed nonegotiateend The Dell switch has the follow config on the trunk port Ten1/0/1: speed 1000description "uplink_to_16thFL-Cisco"switchport mode trunkswitchport trunk allowed vlan 10,20,25   This is working fine. I can pass traffic from the VLAN 10 on the dell switches through the trunk. Now I'm trying to figure out voice vlan on the Dells. On a Cisco switch, I'm used to configuring the access vlan and the voice vlan on the interface. I have interface Gi1/0/1 configured on the Dell switch as follows: switchport voice detect autospanning-tree portfastswitchport general allowed vlan add 10,20,25 taggedswitchport access vlan 10voice vlan 20 My previous experience with Cisco would lead me to believe the phone should end up on vlan 20 and the PC tethered to the phone should get the data vlan 10.   I get the following errors on the Dell switch:   <187> Jun 23 03:12:20 172.16.0.1-1 DOT1Q[isdpTask]: dot1q_api.c(724) 1025 %% Port(Gi1/0/1) with switchport mode Access cannot participate in any vlan <190> Jun 23 03:12:20 172.16.0.1-1 VOICEVLAN[isdpTask]: voice_vlan.c(167) 1026 %% Failed to add the vlan 20 to the interface Gi1/0/1 <187> Jun 23 03:13:20 172.16.0.1-1 DOT1Q[isdpTask]: dot1q_api.c(724) 1027 %% Port(Gi1/0/1) with switchport mode Access cannot participate in any vlan <190> Jun 23 03:13:20 172.16.0.1-1 VOICEVLAN[isdpTask]: voice_vlan.c(167) 1028 %% Failed to add the vlan 20 to the interface Gi1/0/1   I've dug around and understand that the Dell switch will not allow a voice vlan when the port is in access mode. I've tried various configurations of switchport general mode and can get the phone to come up on the right vlan, but the tethered PC no longer can get a DHCP address from the vlan10 scope. Any help / guidance here is appreciated.
N2048 with voice vlan trunk to Cisco Switch