Chapter 1 MAINTENANCE SERVICES
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NWA-033627-001 Rev.4.0
95ch1001.fm
PING COMMAND
(9) ICMP TYPE used in this feature is as follows.
List of ICMP TYPE
ICMP
TYPE
CLASSIFI-
CATION
GENERAL DESCRIPTION
MEANING
0
Reply
Reply to the echo request by exe-
cuting the ping command (echo
reply)
• Ping reply (ping OK)
3
Reply
(error)
Reply message resulting by the ping
request has not arrived at a destina-
tion.
ICMP TYPE=3 is replied if the ping
request is rejected by firewall pro-
tection. And no reply is received if
the ping request cannot arrive at a
destination or ping request is disre-
garded by firewall protection.
• Network unreachable
• Host unreachable
• Protocol unusable
• Port unusable
• Fragmentation failed
• Source routing failed
• Destination network unknown
• Destination host unknown
• Source host isolated from network
• Rejection of destination network
• Rejection of destination host
• Network unreachable for TOS
NOTE 2
• Communication administratively
prohibited by filtering
• Host precedence violation
• Precedence cutoff in effect
11
Reply
(error)
Reply message resulting by time
excess.
The message of packet discard
caused by TTL (Time To Live)
becomes 0 during transit, or the
message of time excess caused by
TTL becomes 0 during waiting for
lost fragments for re-assembly.
• TTL becomes 0 during transit
• TTL becomes 0 during waiting for
lost fragments for re-assembly.
Continued on next page
JULY/17/2009