1IP-NEIGHBOUR(8) Linux IP-NEIGHBOUR(8)
2
6 ip-neighbour - neighbour/arp tables management.
7
9 ip [ OPTIONS ] neigh { COMMAND | help }
10 ip neigh { add | del | change | replace } { ADDR [ lladdr LLADDR ] [
13 nud STATE ] | proxy ADDR } [ dev DEV ]
14 ip neigh { show | flush } [ proxy ] [ to PREFIX ] [ dev DEV ] [ nud
16 STATE ] [ vrf NAME ]
17 STATE := { permanent | noarp | stale | reachable | none | incomplete |
19 delay | probe | failed }
20
23 The ip neigh command manipulates neighbour objects that establish bind‐
24 ings between protocol addresses and link layer addresses for hosts
25 sharing the same link. Neighbour entries are organized into tables.
26 The IPv4 neighbour table is also known by another name - the ARP table.
27 The corresponding commands display neighbour bindings and their proper‐
30 ties, add new neighbour entries and delete old ones.
31 ip neighbour add
34 add a new neighbour entry
35 ip neighbour change
37 change an existing entry
38 ip neighbour replace
40 add a new entry or change an existing one
41 These commands create new neighbour records or update existing
43 ones.
44 to ADDRESS (default)
47 the protocol address of the neighbour. It is either an
48 IPv4 or IPv6 address.
49 dev NAME
52 the interface to which this neighbour is attached.
53 lladdr LLADDRESS
56 the link layer address of the neighbour. LLADDRESS can
57 also be null.
58 nud STATE
61 the state of the neighbour entry. nud is an abbreviation
62 for 'Neighbour Unreachability Detection'. The state can
63 take one of the following values:
64 permanent
67 the neighbour entry is valid forever and can be
68 only be removed administratively.
69 noarp the neighbour entry is valid. No attempts to vali‐
71 date this entry will be made but it can be removed
72 when its lifetime expires.
73 reachable
75 the neighbour entry is valid until the reachabil‐
76 ity timeout expires.
77 stale the neighbour entry is valid but suspicious. This
79 option to ip neigh does not change the neighbour
80 state if it was valid and the address is not
81 changed by this command.
82 none this is a pseudo state used when initially creat‐
84 ing a neighbour entry or after trying to remove it
85 before it becomes free to do so.
86 incomplete
88 the neighbour entry has not (yet) been vali‐
89 dated/resolved.
90 delay neighbor entry validation is currently delayed.
92 probe neighbor is being probed.
94 failed max number of probes exceeded without success,
96 neighbor validation has ultimately failed.
97 ip neighbour delete
100 delete a neighbour entry
101 The arguments are the same as with ip neigh add, except that
103 lladdr and nud are ignored.
104 Warning: Attempts to delete or manually change a noarp entry
107 created by the kernel may result in unpredictable behaviour.
108 Particularly, the kernel may try to resolve this address even on
109 a NOARP interface or if the address is multicast or broadcast.
110 ip neighbour show
113 list neighbour entries
114 to ADDRESS (default)
116 the prefix selecting the neighbours to list.
117 dev NAME
120 only list the neighbours attached to this device.
121 vrf NAME
124 only list the neighbours for given VRF.
125 proxy list neighbour proxies.
128 unused only list neighbours which are not currently in use.
131 nud STATE
134 only list neighbour entries in this state. NUD_STATE
135 takes values listed below or the special value all which
136 means all states. This option may occur more than once.
137 If this option is absent, ip lists all entries except for
138 none and noarp.
139 ip neighbour flush
142 flush neighbour entries
143 This command has the same arguments as show. The differences
144 are that it does not run when no arguments are given, and that
145 the default neighbour states to be flushed do not include perma‐
146 nent and noarp.
147 With the -statistics option, the command becomes verbose. It
150 prints out the number of deleted neighbours and the number of
151 rounds made to flush the neighbour table. If the option is given
152 twice, ip neigh flush also dumps all the deleted neighbours.
153
156 ip neighbour
157 Shows the current neighbour table in kernel.
158 ip neigh flush dev eth0
160 Removes entries in the neighbour table on device eth0.
161
164 ip(8)
165
168 Original Manpage by Michail Litvak <mci@owl.openwall.com>
169iproute2 20 Dec 2011 IP-NEIGHBOUR(8)