Control messages

Control messages
Type Code Status Description
0 Echo 0 Echo reply (used to ping)
1 and 2 unassigned Reserved
3 – Destination Unreachable 0 Destination network unreachable
1 Destination host unreachable
2 Destination protocol unreachable
3 Destination port unreachable
4 Fragmentation required, and DF flag set
5 Source route failed
6 Destination network unknown
7 Destination host unknown
8 Source host isolated
9 Network administratively prohibited
10 Host administratively prohibited
11 Network unreachable for ToS
12 Host unreachable for ToS
13 Communication administratively prohibited
14 Host Precedence Violation
15 Precedence cutoff in effect
4 – Source Quench 0 deprecated Source quench (congestion control)
5 – Redirect Message 0 Redirect Datagram for the Network
1 Redirect Datagram for the Host
2 Redirect Datagram for the ToS & network
3 Redirect Datagram for the ToS & host
6 deprecated Alternate Host Address
7 unassigned Reserved
8 – Echo Request 0 Echo request (used to ping)
9 – Router Advertisement 0 Router Advertisement
10 – Router Solicitation 0 Router discovery/selection/solicitation
11 – Time Exceeded 0 TTL expired in transit
1 Fragment reassembly time exceeded
12 – Parameter Problem: Bad IP header 0 Pointer indicates the error
1 Missing a required option
2 Bad length
13 – Timestamp 0 Timestamp
14 – Timestamp Reply 0 Timestamp reply
15 – Information Request 0 deprecated Information Request
16 – Information Reply 0 deprecated Information Reply
17 – Address Mask Request 0 deprecated Address Mask Request
18 – Address Mask Reply 0 deprecated Address Mask Reply
19 reserved Reserved for security
20 through 29 reserved Reserved for robustness experiment
30 – Traceroute 0 deprecated Information Request
31 deprecated Datagram Conversion Error
32 deprecated Mobile Host Redirect
33 deprecated Where-Are-You (originally meant for IPv6)
34 deprecated Here-I-Am (originally meant for IPv6)
35 deprecated Mobile Registration Request
36 deprecated Mobile Registration Reply
37 deprecated Domain Name Request
38 deprecated Domain Name Reply
39 deprecated SKIP Algorithm Discovery Protocol, Simple Key-Management for Internet Protocol
40 Photuris, Security failures
41 experimental ICMP for experimental mobility protocols such as Seamoby [RFC4065]
42 through 252 unassigned Reserved
253 experimental RFC3692-style Experiment 1 (RFC 4727)
254 experimental RFC3692-style Experiment 2 (RFC 4727)
255 reserved Reserved