If your IP address changes, for whatever reason, you can become locked out of your site's Control Panel or even the entire site if you have the Client Side IP Locker enabled. To get around this you have to update the database with the below SQL:
UPDATE `exp_securitee_settings` SET setting_value = '0' WHERE setting_key = 'enable_cp_ip_locker'
The above disables the CP IP locker so it's important that you enable immediately. When you do though your current IP will be added to the allowed list so you won't have to issues with access again.