Network Link Down or DHCP Failed

These two messages appear on different types of phones:

Polycom - Network Link Down

Aastra - DHCP Failed

If you see either one of these messages displayed, the very first thing you should check is if the Ethernet Cable is plugged in to the correct port on the back of the phone.

Please see the following two reference images for guidance.

Aastra:

Open

Polycom:

Open