3Com Switch 8800 Advanced Software V5 Configuration Guide

79
SYSTEM MAINTENANCE AND
DEBUGGING
When maintaining and debugging the system, go to these sections for
information you are interested in:
■ “System Maintaining and Debugging Overview” on page 1023
■ “System Maintaining and Debugging” on page 1025
■ “System Maintaining Example” on page 1026
System Maintaining
and Debugging
Overview
Introduction to System
Maintaining and
Debugging
You can use the ping command and the tracert command to verify the current
network connectivity.
The ping command
You can use the ping command to verify whether a device with a specified
address is reachable, and to examine network connectivity.
The ping command involves the following steps in its execution:
1 The source device sends an ICMP echo request to the destination device.
2 If the network is functioning properly, the destination device responds by sending
an ICMP echo reply to the source device after receiving the ICMP echo request.
3 If there is network failure, the source device displays timeout or destination
unreachable.
4 Display related statistics.
Output of the ping command includes:
■ Information on the destination’s responses towards each ICMP echo request, if
the source device has received the ICMP echo reply within the timeout time, it
displays the number of bytes of the echo reply, the message sequence number,
Time to Live (TTL), and the response time.
■ If within the period set by the timeout timer, the destination device has not
received the ICMP response, it displays the prompt information.
■ The ping command can apply to the destination’s name or IP address. If the
destination’s name is unknown, the prompt information is displayed.
■ The statistics during the ping operation, which include number of packets sent,
number of echo reply messages received, percentage of messages not received,
the minimum, average, and maximum response time.