I've got VLANs working on my internet network, with VLAN1 untagged (native), and a few others tagged. Most of my infrastructure is Cisco SG300 and SG500 switches. I've currently got my NV3430 working using:
ETH2 (WAN) to a port using an untagged port on the WAN VLAN (926)
ETH1 (LAN) to a port using an untagged port on the LAN VLAN (1)
I'd like to turn on VLAN trunking on ETH1 (LAN), so the native VLAN is 1, untagged, and other VLANs are tagged.