IP Addressing

IP VLSM Diagram Classfull Addresses Private Addresses Classless Subnets /24 - /28 /29 /30 Classless Supernets

Private IP Networks

The following three IP ranges are reserved by Internet Assigned Numbers Authority (IANA) according to RFC 1918.  These IP addresses are not routable over the Internet, so they will not conflict with other sites using these ranges.  To access the Internet with these ranges, you need a Network Address Translation (NAT) device or proxy server, etc.

Private IP Address Ranges (RFC 1918)

Class	From	To	CIDR Mask	Decimal Mask
Class A (24 Bit)	10.0.0.0	10.255.255.255	/8	255.0.0.0
Class B (20 Bit)	172.16.0.0	172.31.255.255	/12	255.240.0.0
Class C (16 Bit)	192.168.0.0	192.168.255.255	/16	255.255.0.0

 

Automatic IP assignment (RFC 3330)

This range is reserved as a Link Local Block for auto-configuration or when a DHCP server can't be found. It is not recommended for normal configuration but is useful in determining if a connection to a DHCP server is not working.

Class	From	To	CIDR Mask	Decimal Mask
Class B (20 Bit)	169.254.0.0	169.254.255.255	/16	255.255.0.0