Ip Address And Subnet Mask; Ip Address Assignment - Nortel BSR252 Configuration - Basics

IP address and subnet mask

Similar to the way houses on a street share a common street name, so too do
computers on a LAN share one common network number.
Where you obtain your network number depends on your particular situation. If
the ISP or your network administrator assigns you a block of registered IP
addresses, follow their instructions in selecting the IP addresses and the subnet
mask.
If the ISP did not explicitly give you an IP network number, you most likely have
a single user account and the ISP assigns you a dynamic IP address when the
connection is established. The Internet Assigned Number Authority (IANA)
reserved this block of addresses specifically for private use; do not use any other
number unless you are told otherwise. For example, you select 192.168.1.0 as the
network number; which covers 254 individual addresses from 192.168.1.1 to
192.168.1.254 (0 and 255 are reserved). In other words, the first three numbers
specify the network number while the last number identifies an individual
computer on that network.
After you select the network number, pick an IP address that is easy to remember,
for instance, 192.168.1.1, for your Business Secure Router. Make sure that no
other device on your network is using that IP address.
The subnet mask specifies the network number portion of an IP address. Your
Business Secure Router computes the subnet mask automatically based on the IP
address that you entered. You do not need to change the subnet mask computed by
the Business Secure Router unless you are instructed to do so.

IP address assignment

A static IP is a fixed IP that your ISP gives you. A dynamic IP is not fixed; the ISP
assigns you a different one each time. The Single User Account feature can be
enabled or disabled if you have either a dynamic or static IP. However, the
encapsulation method assigned influences your choices for IP address and ENET
ENCAP gateway.
Nortel Business Secure Router 252 Configuration — Basics
Chapter 3 Wizard setup 57