Administrator's Guide

Appendix C. Lists of Reserved Ports, ICMP Types and Codes, and Internet Protocols
Type Name Reference
19 Reserved (for Security) [Solo]
20-29 Reserved (for Robustness Experiment) [ZSu]
30 Traceroute [RFC1393]
31 Datagram Conversion Error [RFC1475]
32 Mobile Host Redirect [David Johnson]
33 IPv6 Where-Are-You [Bill Simpson]
34 IPv6 I-Am-Here [Bill Simpson]
35 Mobile Registration Request [Bill Simpson]
36 Mobile Registration Reply [Bill Simpson]
37 Domain Name Request [Simpson]
38 Domain Name Reply [Simpson]
39 SKIP [Markson]
40 Photuris [RFC2521]
41-255 Reserved [JBP]
ICMP codes
Some ICMP types have codes attached.
ICMP type Name Code Description
0 Echo Reply 0 No Code
1 Unassigned
2 Unassigned
3 Destination Unreachable 0 Net Unreachable
1 Host Unreachable
2 Protocol Unreachable
3 Port Unreachable
4 Fragmentation Needed and
Don’t Fragment was Set
5 Source Route Failed
6 Destination Network
Unknown
7 Destination Host Unknown
8 Source Host Isolated
9 Communication with
Destination Network is
Administratively Prohibited
10 Communication with
Destination Host is
Administratively Prohibited
340