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Table Of Contents  The TCP/IP Guide
 9  TCP/IP Lower-Layer (Interface, Internet and Transport) Protocols (OSI Layers 2, 3 and 4)
      9  TCP/IP Internet Layer (OSI Network Layer) Protocols
           9  Internet Control Message Protocol (ICMP/ICMPv4 and ICMPv6)
                9  ICMP Concepts and General Operation

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ICMP Overview, History, Versions and Standards
(Page 3 of 3)

Other Standards That Define ICMP Messages

Both versions of the protocol define a general messaging system that was designed to be expandable. This means that in addition to the messages defined in the ICMP standards themselves, other protocols may also define message types used in ICMP. Some of the more important of these are shown in Table 85.

Table 85: Non-ICMP Internet Standards That Define ICMP Messages

ICMP Version of Message Types Defined

RFC Number


ICMP Message Types Defined



Internet Standard Subnetting Procedure

Address Mask Request, Address Mask Reply


ICMP Router Discovery Messages

Router Advertisement, Router Solicitation


Traceroute Using an IP Option



Requirements for IP Version 4 Routers

Defines three new codes (subtypes) for the Destination Unreachable message.



Neighbor Discovery for IP Version 6 (IPv6)

Router Advertisement, Router Solicitation, Neighbor Advertisement, Neighbor Solicitation, Redirect


Router Renumbering for IPv6

Router Renumbering

The topic on ICMP message classifications, types and codes includes a full list of the ICMPv4/ICMPv6 message types covered in this Guide and the standards that define each.

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ICMP Concepts and General Operation
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