3Com 5500G-EI Command Reference Guide - Page 452

452 CHAPTER 12: USING SYSTEM MANAGEMENT COMMANDS View All views Parameter -a source-IP: Configure the source IP address used by tracert command. -f: Configure to verify the -f switch, first-TTL specifies an initial TTL, ranging from 0 to the maximum TTL. -m: Configure to verify the -m switch, max-TTL specifies a maximum TTL larger than the initial TTL. -p: Configure to verify the -p switch, port is an integer host port number. Generally, user need not modify this option. -q: Configure to verify the -q switch, nqueries is an integer specifying the number of query packets sent, larger than 0. -w: Configure to verify the -w switch, timeout is an integer specifying IP packet timeout in seconds, larger than 0. string: IP address of the destination host or the hostname of the remote system. Description Use the tracert command to check the reachability of network connection and troubleshoot the network. User can test gateways passed by the packets transmitted from the host to the destination. By default, when the parameters are not specified, first-TTL is 1, max-TTL is 30, port is 33434, nqueries is 3 and timeout is 5s. The tracert command sends a packet with TTL 1, and the first hop will send an ICMP error message back to indicate this packet cannot be transmitted (because of TTL timeout). Then this packet will be sent again with TTL 2, and the second hop will indicate a TTL timeout error. Perform this operation repeatedly till reaching the destination. These processes are operated to record the source address of each ICMP TTL timeout so as to provide a path to the destination for an IP packet. After the ping command finds some error on the network, perform tracert to locate the error. The output of the tracert command includes IP address of all the gateways to the destination. If a certain gateway times out, output "***".