Config Mode
When in Config Mode a node will neither participate in the mesh nor connect to the VPN using the WAN port. Instead, it’ll offer a web interface on the LAN port to aid configuration of the node.
Whether a node is in Config Mode can be determined by a characteristic blinking sequence of the SYS LED:

Activating Config Mode
Config Mode is automatically entered at the first boot. You can re-enter Config Mode by pressing and holding the RESET/WPS/DECT button for about three seconds. The device should reboot (all LEDs will turn off briefly) and Config Mode will be available.
If you have access to the console of the node, there is the
gluon-enter-setup-mode
command, which reboots a node into Config Mode.
Port Configuration
In general, Config Mode will be offered on the LAN ports. However, there are two practical exceptions:
Devices with just one network port will run Config Mode on that port.
Devices with PoE on the WAN port will run Config Mode on the WAN port instead.
Accessing Config Mode
Config Mode can be accessed at http://192.168.1.1. The node will offer DHCP to clients. Should this fail, you may assign an IP from 192.168.1.0/24 to your computer manually.

Advanced Config Options
Depending on the installed packages, the advanced config mode allows to configure packages further.
gluon-web-wifi-config enable radios used for wifi and mesh as well as outdoor mode
gluon-web-network allows to configure the used roles (uplink, mesh, client) on each interface
gluon-web-admin allows to enter SSH keys or set a password in the Remote access section
gluon-web-cellular allows to configure SIM card / WWAN settings on supported cellular devices
The advanced config does also allow to upload a sysupgrade file to update the firmware to a different version.