Private Ip Network Addresses - Lucent Technologies SLC ConnectReach User & Service Manual

IP Network Addresses
IP Network Addresses Description

Private IP Network Addresses

Description
A "private" network is one in which devices on a local area network (LAN) either
do not require any access to other networks, or the devices need access to only a
limited set of internetwork services that can be handled by an application proxy
such as NAT. Examples of such services include email, World Wide Web, FTP,
and Telnet connections.
In a private network, addresses are obtained from a common pool of addresses;
and although the addresses are always unique among the devices on the LAN,
they are not guaranteed to be unique on the Internet. Therefore, to prevent
confusion over packet destinations, these private addresses cannot be visible to
the Internet. Instead, the application proxy must intercept all incoming traffic and
manage the mapping of packets to the appropriate destination on the private
network.
This allows an Internet service provider to allocate only one unique IP address to
the site: the address of the SLC
provider. A range of IP addresses from the common pool are then used for all of
the user devices on the LAN.
Suggested private networks are defined in RFC 1918, which lists the pool of IP
addresses from which private network addresses may be selected. This pool is
shown in the following table.
.
$GGUHVV &ODVV
&ODVV $  WKURXJK 
&ODVV %  WKURXJK 
&ODVV &   WKURXJK  
The default IP address assigned to the SLC ConnectReach system (192.168.0.1)
is a class C private network address. If the SLC ConnectReach system is
configured to run dynamic host configuration protocol (DHCP) and use private
network addresses, the addresses allocated by DHCP are derived from the same
class C network.
® ™
ConnectReach system on its link to the service
5DQJH RI $GGUHVVHV
363-208-050
Issue 4 June 2002 A-9