Some of the larger Grandstream ATAs come with two network ports. To successfully provision these devices, you’ll need to ensure the ethernet cable is connected to the correct port.
HT818:
For the HT818, connect the ethernet cable to the network port on the right, marked with the globe-like circular symbol.
HT812:
For the HT812, connect the ethernet cable to the network port on the right, marked with the globe-like circular symbol.
HT812v2:
For the HT812v2, connect the ethernet cable to the network port on the right, labelled NET1.