Connected: An Internet Encyclopedia
4.3.1 INTRODUCTION

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4.3.1 INTRODUCTION

4.3.1 INTRODUCTION

ICMP is an auxiliary protocol, which provides routing, diagnostic and error functionality for IP. It is described in [INTERNET:8]. A router MUST support ICMP.

ICMP messages are grouped in two classes that are discussed in the following sections:

ICMP error messages:

   Destination Unreachable     Section 4.3.3.1
   Redirect                    Section 4.3.3.2
   Source Quench               Section 4.3.3.3
   Time Exceeded               Section 4.3.3.4
   Parameter Problem           Section 4.3.3.5
   ICMP query messages:
   Echo                        Section 4.3.3.6
   Information                 Section 4.3.3.7
   Timestamp                   Section 4.3.3.8
   Address Mask                Section 4.3.3.9
   Router Discovery            Section 4.3.3.10
General ICMP requirements and discussion are in the next section.


Next: 4.3.2 GENERAL ISSUES

Connected: An Internet Encyclopedia
4.3.1 INTRODUCTION