traceroute6(8) manual page

The traceroute6 utility uses the IPv6 protocol hop limit field to elicit an ICMPv6 TIME_EXCEEDED response from each gateway along the path to some host.

The only mandatory parameter is the destination host name or IPv6 address. The default probe datagram carries 20 bytes of payload, in addition 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 default.

-d

Debug mode.

-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

Print both host hostnames and numeric addresses. Normally traceroute6 prints only hostnames if -n is not specified, and only numeric addresses if -n is specified.

-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-connected network, an error is returned. This option corresponds to the SO_DONTROUTE socket option; it can be used to ping a local 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.

!amp; This is printed if the hop limit is <= 1 on a port unreachable 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.

“	Never write it in C if you can do it in `awk'; Never do it in `awk' if `sed' can handle it; Never use `sed' when `tr' can do the job; Never invoke `tr' when `cat' is sufficient; Avoid using `cat' whenever possible.	”
— Taylor's Laws of Programming

Manual Pages — TRACEROUTE6

NAME

CONTENTS

SYNOPSIS

DESCRIPTION

EXIT STATUS

SEE ALSO

HISTORY

-a
	Turn on AS# lookups for each hop encountered.
-A as_server
	Turn on AS# lookups and use the given server instead of the default.
-d
	Debug mode.
-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
	Print both host hostnames and numeric addresses. Normally traceroute6 prints only hostnames if -n is not specified, and only numeric addresses if -n is specified.
-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-connected network, an error is returned. This option corresponds to the `SO_DONTROUTE` socket option; it can be used to ping a local 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.

!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.
!amp;	This is printed if the hop limit is <= 1 on a port unreachable 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.