3Com Switch 7750 Configuration Guide Guide

NETWORK CONNECTIVITY TEST

Network Connectivity

Test

ping You can use the ping command to check the network connectivity and the

reachability of a host.

This command can output the following results:

■ Response status for each ping packet. If no response packet is received within

the timeout time, the message "Request time out" is displayed. Otherwise, the

number of data bytes, packet serial number, TTL (time to live) and response

time of the response packet are displayed.

■ Final statistics, including the numbers of sent packets and received response

packets, the irresponsive packet percentage, and the minimum, average and

maximum values of response time.

tracert You can use the tracert command to trace the gateways a packet passes during

its journey from the source to the destination. This command is mainly used to

check the network connectivity. It can help you locate the trouble spot of the

network.

The executing procedure of the tracert command is as follows: First, the source

host sends a data packet with the TTL of 1, and the first hop device returns an

ICMP error message indicating that it cannot forward this packet because of TTL

timeout. Then, the source host resends the packet with the TTL of 2, and the

second hop device also returns an ICMP TTL timeout message. This procedure

goes on and on until the packet gets to the destination. During the procedure, the

system records the source address of each ICMP TTL timeout message in order to

offer the path that the packet passed through to the destination.

Table 613 The ping command

Operation Command

Support IP protocol

-i interface-type interface-number | -n | - p

-tos tos | -v | ip ]* host-ip

Support IPX protocol

ping ipx ipx-address [ -c count | -s packetsize

| -t timeout ]*

Support CLNS protocol ping clns nsap-address