There are three address ranges designated as private as per RFC 1918:
10.0.0.0
…10.255.255.255
(10/8
) - (Class A network that start with10.
)172.16.0.0
…172.31.255.255
(172.16/12
) - (Class B networks that start with172.16.
)192.168.0.0
…192.168.255.255
(192.168/16
) - (Class C networks that start with192.168.
)