Operator`s manual

6-1
June 1997
Part No. 002-0690-201
TROUBLESHOOTING
SECTION 6 TROUBLESHOOTING
6.1 PING
6.1.1 PING TROUBLESHOOTING TECH-
NIQUES
Ping (packet Internet groper) sends a message to
a device and waits for a response. The response will
indicate that the network connection is working or that
a problem was detected. The ping messages and
responses are ICMP (Internet Control Message Proto-
col) echo messages and their replies.
If the device pinged does not respond, there could
be a problem in several areas. Figure 6-1 shows the
path of a ping from the host computer to a site com-
puter. If the site computer does not respond, trying to
ping the other addresses may show that the problem is
somewhere between the host computer and the site
computer.
To verify that the IP stack in the current device is
functioning properly, ping address 127.0.0.1. (The cur-
rent device is the device that sends the ping message.)
6.1.2 PING PROGRAM OPERATION
Ping is controlled by moving the cursor over the
desired map icon, clicking the right mouse button, and
selecting Ping. Alternatively, select a map icon and
then select menu item Monitor -> Ping.
The Ping window is used to start/stop pings and
set ping options. The bottom of the window shows the
number of pings sent, the number of pings received,
and the percentage of data lost. These numbers are
reset to zero when a ping is started.
Start/Stop pings: This is a toggle operation that is
selected by clicking the menu item Start or Stop, in the
Ping window. Alternatively, click on the hexagon
(stop-sign shaped) red (for stop) or green (for start)
button.
If a response is received from the device, a mes-
sage similar to the following will appear in the Ping
window.
reply from 100.100.103.2: sequence = 0 round-
trip time = 30 ms
round-trip min/avg/max = 30/30/30 ms
The first line includes the network address of the
pinged device (100.100.103.2), the number of the ping
(sequence = 0), and the time it took between when the
ping was sent and the response was received (round-
trip time = 30 ms). If the continuous option has been
selected, the sequence number will increase for each
ping.
The second line shows the minimum, average,
and maximum times for round-trip.
If a device is pinged and no response is received,
a message similar to the following will appear in the
Ping window.
1 packet transmitted,
0 packets received 100% packet loss
Figure 6-1 TROUBLESHOOT BY PINGING SEVERAL IP ADDRESSES
Host Computer Site ComputerRouterRouter
100.100.201.200 100.100.202.100
100.100.202.1
100.100.102.2
100.100.201.1
100.100.102.1