The traceroute Command

The traceroute command was introduced with the release 10.0 of Cisco IOS and can be used to find the route between IP devices. The traceroute command can be executed in user and privileged exec modes, but in privileged exec mode, you can use the extended traceroute, which is more flexible and informative. Initially, traceroute was available only for the IP protocol but since release 12.0 of Cisco IOS, traceroute is also available for IPX. This command can be very useful in troubleshooting by determining where along a particular network path a particular problem might be as the traceroute command displays a hop-by-hop path through an IP network from the switch to a specific destination host. The syntax for the traceroute command is:

traceroute [ -n ] [- w wait_time ] [ -i initial_ttl ] [ -m max_ttl ] [ -p dest_port ] [ -q nqueries ] [ -t tos ] ip_address [ data_size ]

Parameter Description
-n Prevents traceroute from performing a DNS lookup for each hop on the path. Only numerical IP addresses are printed.
-w wait_time Specifies the amount of time that traceroute will wait for an ICMP response message. The allowed range for wait time is 1 to 300 seconds; the default is 5.
-i initial_ttl Causes traceroute to send ICMP datagrams with a TTL value equal to initial_ttl instead of the default TTL of 1. This causes traceroute to skip processing for hosts that are less than initial_ttl hops away.
-m max_ttl Specifies the maximum TTL value for outgoing ICMP datagrams. The allowed range is 1 to 255; the default value is 30.
-p dest_port Specifies the base UDP destination port number used in traceroute data grams. This value is incremented each time a datagram is sent. The allowed range is 1 to 65535; the default base port is 33434.
-q nqueries Specifies the number of datagrams to send for each TTL value. The allowed range is 1 to 1000; the default is 3.
-t tos Specifies the TOS to be set in the IP header of the outgoing data grams. The allowed range is 0 to 255; the default is 0.
ip_address IP alias or IP address in dot notation of the destination host.
Data_size Number of bytes, in addition to the default of 40 bytes, of the outgoing data grams. The allowed range is 0 to 1420; the default is 0.

TABLE 4.2: Parameters for the traceroute Command

Bookmark this page | Make this your Homepage