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TRACEROUTE6(8)		    System Manager's Manual		TRACEROUTE6(8)

NAME
       traceroute6 -- print the	route IPv6 packets will	take to	a network node

SYNOPSIS
       traceroute6  [-adEIlnNrSTUv]  [-A as_server] [-f	firsthop] [-g gateway]
		   [-m hoplimit] [-p port] [-q probes] [-s  src]  [-t  tclass]
		   [-w waittime] target	[datalen]

DESCRIPTION
       The  traceroute6	 utility  uses	the  IPv6  protocol hop	limit field to
       elicit an ICMP6 TIME_EXCEEDED response from each	gateway	along the path
       to some host.

       The only	mandatory parameter is the destination host name or  IPv6  ad-
       dress.	The default probe datagram carries 20 bytes of payload,	in ad-
       dition to the IPv6 header.  The size of the payload can be specified by
       giving a	length (in bytes) after	the destination	host name.

       Other options are:

       -a      Turn on AS# lookups for each hop	encountered.

       -A as_server
	       Turn on AS# lookups and use the given server instead of the de-
	       fault.

       -d      Debug mode.

       -E      Detect ECN bleaching.  Set the IPTOS_ECN_ECT1 Explicit  Conges-
	       tion  Notification  (ECN)  bits (01), and report	if the hop has
	       bleached	(00) or	mangled	(10) them, or if  it  is  experiencing
	       congestion (11).	 Otherwise, report that	it passed the bits ap-
	       propriately.   If  -t  is also specified, the corresponding ECN
	       bits will be replaced.

       -f firsthop
	       Specify how many	hops to	skip in	trace.

       -g gateway
	       Specify intermediate gateway.   Please  note  that  traceroute6
	       tries to	use routing headers.

       -I      Use ICMP6 ECHO instead of UDP datagrams.

       -l      Ignored for backward compatibility.

       -m hoplimit
	       Specify	maximum	hoplimit, up to	255.  The default is the value
	       of the net.inet6.ip6.hlim sysctl(8) (the	same default used  for
	       TCP connections).

       -n      Do not resolve numeric address to hostname.

       -N      Use a packet with no upper layer	header for the probes, instead
	       of UDP datagrams.

       -p port
	       Set SCTP/TCP/UDP	port number to port.

       -q probes
	       Set the number of probe per hop count to	probes.

       -r      Bypass the normal routing tables	and send directly to a host on
	       an  attached  network.	If  the	host is	not on a directly-con-
	       nected network, an error	is returned.  This option  corresponds
	       to the SO_DONTROUTE socket option; it can be used to ping a lo-
	       cal  host  through  an  interface  that has no route through it
	       (e.g., after the	interface was dropped by a routing daemon).

       -s src  Src specifies the source	IPv6 address to	be used.

       -S      Use SCTP	packets	for the	probes.	 The  size  of	probe  packets
	       must be a multiple of 4.	 If datalen is up to 28, probe packets
	       consist	of  a  SHUTDOWN-ACK  chunk possibly bundled with a PAD
	       chunk.  For larger probe	packets, an INIT chunk is used.

       -t tclass
	       tclass specifies	the traffic  class  used  when	sending	 probe
	       packets.	 The value must	be a decimal integer in	the range 0 to
	       255.  The default is 0.

       -T      Use TCP segments	for the	probes.

       -U      Use UDP datagrams for the probes.  This is the default.

       -v      Be verbose.

       -w waittime
	       Specify the delay time between probes.

       This  program  prints the route to the given destination	and the	round-
       trip time to each gateway, in the same manner as	traceroute.

       Here is a list of possible annotations after the	 round-trip  time  for
       each gateway:

	     !N	     Destination Unreachable - No Route	to Host.

	     !P	     Destination Unreachable - Administratively	Prohibited.

	     !S	     Destination Unreachable - Not a Neighbour.

	     !A	     Destination Unreachable - Address Unreachable.

	     !H	     Parameter Problem - Unrecognized Next Header Type.

	     !<num>  ICMP6 unreachable code <num>.

	     !	     This  is  printed	if the hop limit is <= 1 on a port un-
		     reachable message.	 This means that the packet got	to the
		     destination, but that the reply had a hop limit that  was
		     just  large  enough to allow it to	get back to the	source
		     of	the traceroute6.  This was  more  interesting  in  the
		     IPv4  case,  where	some IP	stack bugs could be identified
		     by	this behaviour.

EXIT STATUS
       The traceroute6 utility will exit with 0	on success,  and  non-zero  on
       errors.

SEE ALSO
       ping(8),	traceroute(8)

HISTORY
       The  traceroute6	utility	first appeared in WIDE hydrangea IPv6 protocol
       stack kit.

FreeBSD	15.0		       November	12, 2024		TRACEROUTE6(8)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=traceroute6&manpath=FreeBSD+15.0-RELEASE+and+Ports>

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