Ccna routing and Switching Complete Study Guide

Network Addresses: Special Purpose

Some IP addresses are reserved for special purposes, so network administrators can’t ever 

assign these addresses to nodes. Table 3.4 lists the members of this exclusive little club and 

the reasons why they’re included in it.

Ta b l e   3 . 4     Reserved IP addresses

Address

Function

Network address of all 0s

Interpreted to mean “this network or segment.”

Network address of all 1s

Interpreted to mean “all networks.”

Network 127.0.0.1

Reserved for loopback tests. Designates the local 

node and allows that node to send a test packet to 

itself without generating network traffic.

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Chapter 3 

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  Introduction to TCP/IP