Administrator's Guide

Appendix C. Lists of Reserved Ports, ICMP Types and Codes, and Internet Protocols
ICMP type Name Code Description
11 Destination Network
Unreachable for Type of
Service
12 Destination Host
Unreachable for Type of
Service
13 Communication is
Administratively Prohibited
4 Source Quench 0 No Code
5 Redirect 0 Redirect Datagram for the
Network (or subnet)
1 Redirect Datagram for the
Host
2 Redirect Datagram for the
Type of Service and Network
3 Redirect Datagram for the
Type of Service and Host
6 Alternate Host Address 0 Alternate Address for Host
7 Unassigned
8 Echo 0 No Code
9 Router Advertisement 0 No Code
10 Router Selection 0 No Code
11 Time Exceeded 0 Time to Live exceeded in
Transit
1 Fragment Reassembly Time
Exceeded
12 Parameter Problem 0 Pointer indicates the error
1 Missing a Required Option
2 Bad Length
13 Timestamp 0 No Code
14 Timestamp Reply 0 No Code
15 Information Request 0 No Code
16 Information Reply 0 No Code
17 Address Mask Request 0 No Code
18 Address Mask Reply 0 No Code
19 Reserved (for Security)
20-29 Reserved (for Robustness
Experiment)
30 Traceroute
31 Datagram Conversion Error
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