3Com CoreBuilder 3500, Руководство по внедрению

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530 C
HAPTER
18: D
EVICE
M
ONITORING
Ping
The ping feature is a useful tool for network testing, performance
measurement, and management. It uses the Internet Control Message
Protocol (ICMP) echo facility to send ICMP echo request packets to the IP
destination that you specify. See Chapter 11
for more information about
ICMP.
When a router sends an echo request packet to an IP station using ping,
the router waits for an ICMP echo reply packet. The response indicates
whether the remote IP is available, unreachable, or not responding.
Important
Consideration
When you specify a hostname with ping, the hostname and its associated
IP address must be configured on a network name server. Also, you must
add the IP address on the name server to the list of name server addresses
that are associated with the network domain name. See Domain Name
Servers in Chapter 11.
Using Ping The system provides two ping functions:
■
ping — Uses the hostname or IP address to ping a host with default
options
■
advancedPing — Uses the hostname or IP address to ping a host
with the advanced ping options that you specify
Ping Responses This list gives the possible responses to a ping:
■
If the host is reachable, the system displays information about the
ICMP reply packets and the response time to the ping. The amount of
information depends on whether the quiet option is enabled or
disabled.
■
If the host does not respond, the system displays the ICMP packet
information and this message:
Host is Not Responding.
(You may
see this message if you have not configured your gateway IP address.)
■
If the packets cannot reach the host, the system displays the ICMP
packet information and this message:
Host is Unreachable.
A host
is unreachable when there is no route to that host.