149 \item \verb|neighbour| --- ARP or NDISC cache entry
867 \section{{\tt ip neighbour} --- neighbour/arp tables management}
869 \paragraph{Abbreviations:} \verb|neighbour|, \verb|neighbor|, \verb|neigh|,  argument
872 \paragraph{Object:} \verb|neighbour| objects establish bindings between protocol  argument
874 Neighbour entries are organized into tables. The IPv4 neighbour table
877 The corresponding commands display neighbour bindings
878 and their properties, add new neighbour entries and delete old ones.
887 \subsection{{\tt ip neighbour add} --- add a new neighbour entry\\  argument
888 	{\tt ip neighbour change} --- change an existing entry\\
889 	{\tt ip neighbour replace} --- add a new entry or change an existing one}
894 \paragraph{Description:} These commands create new neighbour records
902 --- the protocol address of the neighbour. It is either an IPv4 or IPv6 address.
906 --- the interface to which this neighbour is attached.
911 --- the link layer address of the neighbour. \verb|LLADDRESS| can also be
916 --- the state of the neighbour entry. \verb|nud| is an abbreviation for ``Neighbour
920 \item \verb|permanent| --- the neighbour entry is valid forever and can be only be removed
922 \item \verb|noarp| --- the neighbour entry is valid. No attempts to validate
924 \item \verb|reachable| --- the neighbour entry is valid until the reachability
926 \item \verb|stale| --- the neighbour entry is valid but suspicious.
927 This option to \verb|ip neigh| does not change the neighbour state if
937 --- add a permanent ARP entry for the neighbour 10.0.0.3 on the device \verb|eth0|.
945 \subsection{{\tt ip neighbour delete} --- delete a neighbour entry}  argument
949 \paragraph{Description:} This command invalidates a neighbour entry.
959 --- invalidate an ARP entry for the neighbour 10.0.0.3 on the device \verb|eth0|.
964  The deleted neighbour entry will not disappear from the tables
977 \subsection{{\tt ip neighbour show} --- list neighbour entries}  argument
981 \paragraph{Description:}This commands displays neighbour tables.
1001 --- only list neighbour entries in this state. \verb|NUD_STATE| takes
1022 The first word of each line is the protocol address of the neighbour.
1024 the neighbour entry identified by the pair (device, address).
1026 \verb|lladdr| is the link layer address of the neighbour.
1028 \verb|nud| is the state of the ``neighbour unreachability detection'' machine
1029 for this entry. The detailed description of the neighbour
1034 \item\verb|none| --- the state of the neighbour is void.
1035 \item\verb|incomplete| --- the neighbour is in the process of resolution.
1036 \item\verb|reachable| --- the neighbour is valid and apparently reachable.
1037 \item\verb|stale| --- the neighbour is valid, but is probably already
1039 \item\verb|delay| --- a packet has been sent to the stale neighbour and the kernel is waiting
1042 The kernel has started to probe the neighbour with ARP/NDISC messages.
1044 \item\verb|noarp| --- the neighbour is valid. No attempts to check the entry
1047 may remove the entry from the neighbour table.
1054 which means that the neighbour introduced itself as an IPv6 router~\cite{RFC-NDISC}.
1076 \subsection{{\tt ip neighbour flush} --- flush neighbour entries}  argument
1080 \paragraph{Description:}This command flushes neighbour tables, selecting
1085 and that the default neighbour states to be flushed do not include
1091 of rounds made to flush the neighbour table. If the option is given
1158 controlled by neighbour unreachability detection and by advice