IP Address

The IP address, something like, is used to address an IP endpoint. The IP address is typically used to address a single network interface card (NIC). Every NIC used to communicate through IP, must have at least one IP address.

One machine can have a lot of IP addresses, as a machine can have more than one NIC, and a NIC can have more than one IP address (however, that's not widely used).

The IP address can be statically assigned to a NIC through system specific configuration, or dynamically assigned using DHCP or APIPA.

IP address classes

  • - Class A
  • - Class B
  • - Class C
  • - Class D
  • - Class E

Special IP addresses

  • - local loopback, should never appear on the network

  • - link local for use with Automatic Private IP Addressing (APIPA)

  • - multicasting RFC1112, transmission to a host group

  • limited broadcast, send to all nodes

Private IP Addresses

The following IP addresses should be used for private networks:

  • - private in Class A
  • - private in Class B
  • - private in Class C

Stupid Tricks Involving IP Addresses

Most operating systems let you specify an IP address as an integer as opposed to the traditional dotted-quad format. For instance, the following commands are equivalent:

 ping 0xc0a80501   # Hexadecimal
 ping 3232236801   # Decimal
 ping 030052002401 # Octal

External Links


What about IPv6? See, for example, RFC 2373. - Guy Harris

Imported from https://wiki.wireshark.org/IP-address on 2020-08-11 23:15:11 UTC