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       ndisc6 - ICMPv6 Neighbor Discovery tool


       ndisc6 [-1mnqv] [-r attempts] [-w wait_ms] < IPv6 address> <iface>


       NDisc6  is  an  Unix  program  which  implements  the  ICMPv6  Neighbor
       Discovery in userland (it is normally done by the kernel). It  is  used
       to  lookup  the link-layer address (layer 2 address, MAC in the case of
       Ethernet) of any on-link IPv6 node.

       The IPv6 address of  the  node  must  be  specified,  as  well  as  the
       networking interface on which to perform the lookup.


       -1 or --single
              Exit as soon as the first advertisement is received (default).

       -h or --help
              Display some help and exit.

       -m or --multiple
              Wait  for  possible  duplicate  advertisements  and print all of

       -n or --numeric
              If the first parameter is not a valid IPv6 address, do  not  try
              to resolve it as a DNS hostname.

       -q or --quiet
              Only  display  link-layer  address.  Display  nothing in case of
              failure.  That is mostly useful when calling the program from  a
              shell script.

       -r attempts or --retry attempts
              Send  ICMPv6 Neighbor Discovery that many times until a reply is
              received, or abort. By default, ndisc6 will try 3  times  before
              aborting  (MAX_MULTICAST_SOLICIT  and  MAX_UNICAST_SOLICIT  from

       -V or --version
              Display program version and license and exit.

       -v or --verbose
              Display verbose information. That is the default.

       -w wait_ms or --wait wait_ms
              Wait wait_ms milliseconds for a response  before  retrying.   By
              default,   ndisc6   waits   1   second   between  each  attempts
              (RETRANS_TIMER from RFC2461).


       If you get no response while you know the remote host is up, it is most
       likely  that  it  is not on-link, that is to say, you must cross one or
       more routers to reach it. By design, IPv6 nodes ignore ICMPv6  Neighbor
       Discovery  packets  received  from  nodes  not  on  the same link (i.e.
       Ethernet segment), for the sake of security. Technically, that is  done
       by ensuring that the Hop limit (TTL) is 255.

       Note  that  you cannot use ndisc6 to lookup the local host’s link-layer


       ndisc6 should be setuid root to allow use by non privileged  users.  It
       will  drop  its  root  privileges before any attempt is made to send or
       receive data from the network  to  reduce  the  possible  impact  of  a
       security vulnerability.


       ping6(8), rdisc6(8), ipv6(7)


       Rémi Denis-Courmont <rdenis at>

       $Id: ndisc6.8 483 2007-08-08 15:09:36Z remi $