TYPE    CODE    MEANING

0       0       ECHO REPLY (ping reply)
3               DESTINATION UNREACHABLE
0               network unreachable
1               host unreachable
2               protocol unreachable
3               port unreachable
4               frag needed
5               source route failed
6               destination network unknown
7               destination host unknown
8               source host isolated
9               destination network administratively prohibited
10              destination host administratively prohibited
11              network unreachable for TOS
12              host unreachable for TOS
13              prohibited by filtering
14              host precedence violation
15              precedence cutoff
4       0       SOURCE QUENCH
5               REDIRECT
        0       network
        1       host
        2       network & TOS
        3       host & TOS
8       0       ECHO REQUEST (ping request)
9       0       ROUTER ADVERTISEMENT
10      0       ROUTER SOLICITATION
11              TIME EXCEEDED
        0       TTL=0 during transmit
        1       TTL=0 during reassembly
12              PARAMETER PROBLEM
13      0       TIMESTAMP REQUEST
14      0       TIMESTAMP REPLY
15      0       INFO REQUEST
16      0       INFO REPLY
17      0       ADDRESS MASK REQUEST
18      0       ADDRESS MASK REPLY