The web UI lists physical and VLAN interfaces and takes a VLAN uplink as a device name (enp2s0.1001); it has IPv6 checkboxes for the WAN and each LAN. router-setup asks whether to create VLANs before WAN and LAN are picked, and whether to enable IPv6. --config-only writes the configuration without installing, which the setup test uses for a PPPoE uplink on a VLAN. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AeFqV9dZrK6nipHkPfyM4F