Linux in a Nutshell, 6th Edition

Name

traceroute

Synopsis

traceroute [options] host [packetsize]

TCP/IP command. Trace route taken by packets to reach network host. traceroute attempts tracing by launching UDP probe packets with a small TTL (time-to-live), then listening for an ICMP “time exceeded” reply from a gateway. host is the destination hostname or the IP number of the host to reach. packetsize is the packet size in bytes of the probe datagram. Default is 40 bytes.

Options

−4, −6

Force IPv4 or IPv6 tracerouting.

-A

Perform AS path lookups.

-d

Turn on socket-level debugging.

-e

Show ICMP extensions.

-f n

Set the initial time-to-live to n hops.

-F

Set the “don’t fragment” bit.

-g addr

Enable the IP LSRR (Loose Source Record Route) option in addition to the TTL tests, to ask how someone at IP address addr can reach a particular target.

-i interface

Specify the network interface for getting the source IP address for outgoing probe packets. Useful with a multihomed host. Also see the -s option.

-I

Use ICMP ECHO requests instead of UDP datagrams.

-m max_ttl

Set maximum time-to-live used in outgoing probe packets to max-ttl hops. Default is 30.

-n

Show numerical addresses; do not look up hostnames. (Useful if DNS is not functioning properly.)

-N n

Send n probe packets simultaneously. The default is 16.

-p port

Set base UDP port number used for probe packets to port. Default is (decimal) 33434.

-q n

Set number of probe packets per hop to the value n. Default is 3.

-r

Bypass normal routing tables and send directly to a host on an attached network. ...