IP address conventions

The system uses a set of IP address conventions to interpret IP address blocks entered using IPv4 CIDR notation or IPv6 prefix length notation, including the addresses that are not entered on the standard network boundary.

  • You can use IPv4 Classless Inter-Domain Routing (CIDR) notation and the similar IPv6 prefix length notation to define address blocks in many places in the system.

  • When you use CIDR or prefix length notation to specify a block of IP addresses, the system uses only the portion of the network IP address specified by the mask or prefix length. For example, if you type 10.1.2.3/8, the system uses 10.0.0.0/8.

  • Cisco recommends using network IP addresses on the bit boundary when employing CIDR or prefix length notation, but the system does not enforce this requirement.