-A Looks up the AS-number (Autonomous System)
for each hop's network address at the whois
server specified by the -h option.
-a If the destination host has multiple
addresses, traceroute probes all addresses
if this option is set. Normally only the
first address as returned by the resolver is
attempted.
-c stoptime Specifies a delay (in seconds) to pause
between probe packets. This may be necessary
if the final destination is a router that
does not accept undeliverable packets in
bursts.
-f Disables IP fragmentation. If the given
packetsize is too big to be handled
unfragmented by a machine along the route,
a "fragmentation needed" status is returned
and the indicator !F is printed. If a gate-
way returns the value of the proper MTU size
to be used, traceroute decreases the packet
size automatically to this new value. If the
proper MTU size is not returned, traceroute
chooses a shorter packet size.
-g gateway Enables the IP LSRR (Loose Source Record
Route) option. This is useful for asking
how somebody else, at the specified gateway,
reaches a particular target.
-h server Specifies the name or IP address of the
whois server that is contacted for the AS-
number lookup, if the -A option is given.
-i initial_ttl Sets the starting time-to-live value to
initial_ttl, to override the default value
of 1. Effectively this skips processing for
those intermediate hosts that are less than
initial_ttl hops away.
-k Keeps the connection to the whois server
permanently open. This makes lookups
considerably quicker, because connection
setup for each individual lookup is not
necessary. However, all whois servers do not
support this feature.
-l Prints the value of the ttl field in each
received packet (this can be used to help
detect asymmetric routing).
-m max_ttl Sets the max time-to-live (max number of
hops) used in outgoing probe packets.
The default is 30 hops, which is the same
default used for TCP connections.
-N Displays the network name for each hop.
If a BIND resolver cannot be reached,
network names are retrieved just from the
/etc/networks file.
-n Prints hop IP addresses numerically rather
than both symbolically and numerically. This
saves a nameserver address-to-name lookup
for each gateway found on the path. It also
prevents a reverse lookup for numeric dotted
quad addresses given on the command line
(destination host, or -g gateway addresses).
-p port Sets the base UDP port number used in
probes (default is 33434). The traceroute
command presumes that nothing is listening
on UDP ports base to base+nhops-1 at
the destination host (so an ICMP "port
unreachable" message is returned to
terminate the route tracing). If another
process is listening on a port in the
default range, use this option to pick an
unused port range.
-Q maxquit Stops probing this hop after maxquit
consecutive timeouts are detected. The
default value is 5. Useful in combination
with -S if you have specified a big nqueries
probe count.
-q nqueries Sets the number of probes launched at each
ttl setting (default is 3).
-r Bypasses the normal routing tables and sends
directly to a host on an attached network.
If the host is not on a directly-attached
network, an error is returned. This option
can be used to ping a local host through an
interface that has no route through it (for
example, after the interface was dropped by
routed(8) or gated(8)).
-S Prints a per-hop minimum/average/maximum
rtt (round-trip time) statistics summary.
This suppresses the per-probe rtt and ttl
reporting. For better statistics you need to
increase the default nqueries probe count.
See also the -Q option.
-s source_addr Uses the following IP address (which must
be given as an IP number, not a hostname)
as the source address in outgoing probe
packets. On hosts with more than one IP
address, use this option to force the source
address to be something other than the IP
address of the interface on which the probe
packet is sent. If the IP address is not one
of this machine's interface addresses, an
error is returned and nothing is sent.
-t tos Sets the type-of-service in probe packets
to the following value (default zero).
The value must be a decimal integer in
the range 0 to 255. Use this option to
determine if different types-of-service
result in different paths. Not all values
of TOS are legal or meaningful. See the IP
specification for definitions. Useful values
are probably -t 16 (low delay) and -t 8
(high throughput).
-v Produces verbose output. Lists any received
ICMP packets other than "time exceeded" and
"unreachable".
-w waittime Sets the time (in seconds) to wait for
a response to a probe. The default is 3
seconds.