Apple.com/support -2100?

in Internet Recovery, these low negative thousands error messages indicate that your provided Wi-Fi Network is inadequate in some fashion, and cannot be used in its current state.

Common problems include:

Hidden Network-name

required use of a proxy server to get Internet access

required use of a login page to get Internet access

Use of a login server or certificate to get Internet access

Use of PPPoE in the Mac to get Internet access (typically only applies to DSL)

Use of Fixed IP address rather than good old DHCP

Variance of the time by more than five minutes

Failure of Router to provide workable DNS server addresses, or providing 0.0.0.0 [may produce -2002f]

If you have an Ethernet port, you may in some cases be able to move your Mac close to the Router and connect to the Router using Ethernet.

Your daughter may have to take it to the help desk and use their Ethernet connection.

Do you see a globe with an exclamation point inside of a triangle? That's the machine looking for Internet Recovery and not finding an Internet connection. It shouldn't normally happen unless there was an attempt to enter Internet Recovery or Apple Hardware Test wasn't seen and it tried to pull it from the internet. It should usually give a chance to select a WiFi SSID if it isn't connected to ethernet, but then it might timeout and display that message.

mbourgie wrote:

That's an Internet Recovery failure. Is it just doing it once or all the time?

Before that does it display “Starting Internet Recovery. This may take a while.”?

Where? When? Details help...