Help

[Liverpool1981]

Hi been using ambit 256 for over year just got back from holiday and Mac had expired no big deal right just changing the Mac would get me back but it hasn't and the weird thing is I've been locked out of my modem I've changed ipv4 ip to 192.168.100.10
255.255255.0
192.168.100.1
But still getting unidentified network any suggestions please