Hirschmann RS20 User Manual page 32

Entering the IP Parameters
Since 1993, RFC 1519 has been using Classless Inter Domain Routing
(CIDR) to provide a solution to get around these problems. CIDR overcomes
these class boundaries and supports classless address ranges.
With CIDR, you enter the number of bits that designate the IP address range.
You represent the IP address range in binary form and count the mask bits
that designate the netmask. The netmask indicates the number of bits that
are identical to the network part for all IP addresses in a given address range.
Example:
IP address, decimal
149.218.112.1
149.218.112.127
CIDR notation: 149.218.112.0/25
The combination of a number of class C address ranges is known as
"supernetting". This enables you to subdivide class B address ranges to a
very fine degree.
32
Network mask,
decimal
255.255.255.128
Mask bits
2.1 IP Parameter Basics
IP address, hexadecimal
10010101 11011010 01110000 00000001
10010101 11011010 01110000 01111111
25 mask bits
Basic Configuration
Release 6.0 07/2010