NAME

       ip-neighbour - neighbour/arp tables management.

SYNOPSIS

       ip [ OPTIONS ] neigh  { COMMAND | help }

       ip neigh { add | del | change | replace } { ADDR [ lladdr LLADDR ] [ nud { permanent | noarp | stale |
               reachable } ] | proxy ADDR } [ dev DEV ]

       ip neigh { show | flush } [ proxy ] [ to PREFIX ] [ dev DEV ] [ nud STATE ]

DESCRIPTION

       The ip neigh command manipulates neighbour objects that establish bindings between protocol addresses and
       link layer addresses for hosts sharing the same link.  Neighbour entries are organized into tables. The
       IPv4 neighbour table is also known by another name - the ARP table.

       The corresponding commands display neighbour bindings and their properties, add new neighbour entries and
       delete old ones.

       ip neighbour add
              add a new neighbour entry

       ip neighbour change
              change an existing entry

       ip neighbour replace
              add a new entry or change an existing one

       These commands create new neighbour records or update existing ones.

       to ADDRESS (default)
              the protocol address of the neighbour. It is either an IPv4 or IPv6 address.

       dev NAME
              the interface to which this neighbour is attached.

       lladdr LLADDRESS
              the link layer address of the neighbour.  LLADDRESS can also be null.

       nud NUD_STATE
              the  state  of  the  neighbour  entry.   nud  is  an  abbreviation  for  'Neighbour Unreachability
              Detection'.  The state can take one of the following values:

       permanent
              the neighbour entry is valid forever and can be only be removed administratively.

       noarp  the neighbour entry is valid. No attempts to validate this entry  will  be  made  but  it  can  be
              removed when its lifetime expires.

       reachable
              the neighbour entry is valid until the reachability timeout expires.

       stale  the  neighbour  entry  is  valid  but  suspicious.   This  option  to ip neigh does not change the
              neighbour state if it was valid and the address is not changed by this command.
              ip neighbour delete - delete a neighbour entry
       This command invalidates a neighbour entry.

       The arguments are the same as with ip neigh add, except that lladdr and nud are ignored.

       Warning: Attempts to delete or manually change a  noarp  entry  created  by  the  kernel  may  result  in
       unpredictable  behaviour.   Particularly,  the  kernel  may  try  to resolve this address even on a NOARP
       interface or if the address is multicast or broadcast.

              ip neighbour show - list neighbour entries

       This command displays neighbour tables.

       to ADDRESS (default)
              the prefix selecting the neighbours to list.

       dev NAME
              only list the neighbours attached to this device.

       proxy  list neighbour proxies.

       unused only list neighbours which are not currently in use.

       nud NUD_STATE
              only list neighbour entries in this state.  NUD_STATE takes values listed  below  or  the  special
              value  all  which  means  all  states.   This  option may occur more than once.  If this option is
              absent, ip lists all entries except for none and noarp.

              ip neighbour flush - flush neighbour entries

       This command flushes neighbour tables, selecting entries to flush by some criteria.

       This command has the same arguments as show.  The differences are that it does not run when no  arguments
       are given, and that the default neighbour states to be flushed do not include permanent and noarp.

       With the -statistics option, the command becomes verbose.  It prints out the number of deleted neighbours
       and the number of rounds made to flush the neighbour table.  If the option is given twice, ip neigh flush
       also dumps all the deleted neighbours.

EXAMPLES

       ip neighbour
              Shows the current neighbour table in kernel.

       ip neigh flush dev eth0
              Removes entries in the neighbour table on device eth0.

SEE ALSO

       ip(8)

AUTHOR

       Original Manpage by Michail Litvak <mci@owl.openwall.com>

iproute2                                           20 Dec 2011                                   IP-NEIGHBOUR(8)