Cisco Cisco Tunnel Terminating Gateway (TTG) Guide De Montage
Initial System Configuration
Configure the Ethernet Management Interface ▀
ASR 5500 Installation Guide ▄
121
CIDR notation is constructed from the IP address and the prefix size, the latter being the number of leading 1 bits of the
routing prefix. The IP address is expressed according to the standards of IPv4 or IPv6. It is followed by a separator
character, the slash (/) character, and the prefix size expressed as a decimal number.
routing prefix. The IP address is expressed according to the standards of IPv4 or IPv6. It is followed by a separator
character, the slash (/) character, and the prefix size expressed as a decimal number.
The address may denote a single, distinct, interface address or the beginning address of an entire network. In the latter
case the CIDR notation specifies the address block allocation of the network. The maximum size of the network is given
by the number of addresses that are possible with the remaining, least-significant bits below the prefix. This is often
called the host identifier.
case the CIDR notation specifies the address block allocation of the network. The maximum size of the network is given
by the number of addresses that are possible with the remaining, least-significant bits below the prefix. This is often
called the host identifier.
For example:
the address specification 192.168.100.1/24 represents the given IPv4 address and its associated routing prefix
192.168.100.0, or equivalently, its subnet mask 255.255.255.0.
the IPv4 block 192.168.0.0/22 represents the 1024 IPv4 addresses from 192.168.0.0 to 192.168.3.255.
the IPv6 block 2001:DB8::/48 represents the IPv6 addresses from 2001:DB8:0:0:0:0:0:0 to
2001:DB8:0:FFFF:FFFF:FFFF:FFFF:FFFF.
::1/128 represents the IPv6 loopback address. Its prefix size is 128, the size of the address itself, indicating that
this facility consists of only this one address. An application sending a packet to this address will get the packet
back after it is looped back by the IPv6 stack. The equivalent IPv4 local host address is 127.0.0.1.
back after it is looped back by the IPv6 stack. The equivalent IPv4 local host address is 127.0.0.1.
The number of addresses of a subnet defined by the mask or prefix can be calculated as 2^address size - mask, in which
the address size for IPv4 is 32 and for IPv6 is 128. For example, in IPv4, a mask of /29 gives: 2^32-29 = 2^3 = 8
addresses.
the address size for IPv4 is 32 and for IPv6 is 128. For example, in IPv4, a mask of /29 gives: 2^32-29 = 2^3 = 8
addresses.