Use Classless Inter-Domain Routing (CIDR) notation when configuring IP addresses for IP range, IPsec, or GRE authentication and for web policies.
CIDR notation specifies:
- A routing prefix to a network
- An IP address or range on the specified network
CIDR syntax consists of an IPv4 or IPv6 address followed by a forward slash and a decimal number. The decimal number specifies the number of bits in the network prefix.
IPv4 network prefixes are allowed to range in size from 8 bits to 32 bits. A 24-bit IPv4 network prefix consists of 256 addresses. IPv6 network prefixes are allowed to range in size from 8 bits to 128 bits. A 120-bit IPv6 network prefix consists of 256 addresses.
|Protocol||Network prefix (bits)||CIDR notation (example)||Specified IP address range|
|IPv4||8-32||127.0.0.0/24||From 127.0.0.0 to 127.0.0.255|