The IP would be on the subnet, just not in the DHCP range.DallasTeleAg said:
...but that IP wouldn't be on the subnet. How can he choose an IP address that is not available on the subnet?
Just download Angry IP Scanner and see which IPs are being used: https://angryip.org/
Subnet is 192.168.1.0/24
DHCP scope is 192.168.1.100 to 192.168.1.200.
He can still use 192.168.1.2 to .99 and .201 to .254 (I'm assuming standard .1 as gateway). He could also do an address within the DHCP range, but most of the home routers aren't smart enough to ping an address before they try to give it out.