Glossary
FRITZ!Box Fon WLAN 7570 vDSL
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IP addresses can be public or private, and also fixed or as-
signed dynamically. See the corresponding entries in the
glossary for more information.
IP addressing
Addressing is one of the main functions of the Internet Pro-
tocol (IP). Internet addresses can be written in decimal, oc-
tal or hexadecimal notation. The FRITZ!Box uses “dotted-
decimal” notation: The four bytes of an address are repre-
sented by decimal numbers separated by dots. The total
volume of Internet addresses, the address space, is sepa-
rated into classes (A, B, C, D, and E). The full set of IP ad-
dresses, called the address space, is grouped into address
classes designated as A, B, C, D and E. Only the first three
of these five address classes are actually used. These
classes can be described as follows:
Properties of IP Address Classes
Every IP address consists of two parts: the network address
and the host address. The sizes of the network address and
the host address are variable, and determined by the first
four bits (of the first byte) of the IP address.
IP
mMasquerading
By means of IP masquerading a computer or LAN can be
protected from unauthorized connection request from the
Internet. Masquerading works by converting the IP address-
es used in a network to one public IP address. From the out-
side it appears that all requests are sent from a single com-
puter.
Classes
Properties
Network Address,
Decimal Value
Class A ad-
dress
Few networks, many hubs
0-127
Class B ad-
dress
Intermediate distribution of
networks and hubs
128-191
Class C ad-
dress
Many networks, few hubs
192-223
