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VMS Help traceroute, FLAGS *Conan The Librarian |
-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 Specifies a delay (in seconds) to pause between
stoptime 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 Enables the IP LSRR (Loose Source Record Route)
gateway 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 Sets the starting time-to-live value to initial_ttl,
initial_ to override the default value of 1. Effectively this
ttl 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_ Sets the max time-to-live (max number of hops) used in
ttl 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 Stops probing this hop after maxquit consecutive
maxquit timeouts are detected. The default value is 5. Useful
in combination with -S if you have specified a big
nqueries probe count.
-q Sets the number of probes launched at each ttl setting
nqueries (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 Uses the following IP address (which must be given as
source_ an IP number, not a hostname) as the source address
addr 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 Sets the time (in seconds) to wait for a response to a
waittime probe. The default is 3 seconds.
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