Canon EOS 90D DSLR Camera with 18-135mm Lens - Manual (Page 485)

485
Responding to Error Messages
21: No address assigned by DHCP server
What to check on the camera
 On the camera, IP address is set to [Auto setting] . Is this the correct
setting?
g If no DHCP server is used, specify the settings after setting the IP
address to [Manual setting] on the camera ( = 462).
What to check on the DHCP server

Is the power of the DHCP server on?
g
Turn on the DHCP server.

Are there enough addresses for assignment by the DHCP server?
g
Increase the number of addresses assigned by the DHCP server.
g
Remove devices assigned addresses by the DHCP server from the
network to reduce the number of addresses in use.

Is the DHCP server working correctly?
g
Check the DHCP server settings to make sure it is working correctly
as a DHCP server.
g
If applicable, ask your network administrator to ensure the DHCP
server is available.