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28 .\" @(#)arp.8 8.1 (Berkeley) 6/6/93
36 .Nd address resolution display and control
54 .Fl s Ar hostname ether_addr
56 .Op Cm blackhole No \&| Cm reject
59 .Fl S Ar hostname ether_addr
61 .Op Cm blackhole No \&| Cm reject
68 utility displays and modifies the Internet-to-Ethernet address translation
69 tables used by the address resolution protocol
71 With no flags, the program displays the current
75 The host may be specified by name or by number,
76 using Internet dot notation.
79 .Bl -tag -width indent
81 The program displays or deletes all of the current
85 A super-user may delete an entry for the host called
92 keyword is specified, only the
96 for this host will be deleted.
100 flag may be combined with the
102 flag to delete all entries.
103 .It Fl i Ar interface
104 Limit the operation scope to the
108 Applicable only to the following operations:
109 display one, display all, delete all.
111 Show network addresses as numbers (normally
113 attempts to display addresses symbolically).
114 .It Fl s Ar hostname ether_addr
117 entry for the host called
119 with the Ethernet address
121 The Ethernet address is given as six hex bytes separated by colons.
122 The entry will be permanent unless the word
124 is given in the command.
127 is given, the entry will be
129 i.e., this system will
133 responding to requests for
135 even though the host address is not its own.
140 in which case the interfaces on this host will be examined,
141 and if one of them is found to occupy the same subnet, its
142 Ethernet address will be used.
145 keyword is also specified, this will create a
146 .Dq "published (proxy only)"
148 This type of entry is created automatically if
150 detects that a routing table entry for
156 keyword is specified the entry will be marked so that traffic to
157 the host will be discarded and the sender will be notified the
161 keyword is similar in that traffic is discarded but the sender is
163 These can be used to block external traffic to a host without
165 .It Fl S Ar hostname ether_addr
170 entry for this host will be deleted first.
174 to be read and multiple entries to be set in the
178 in the file should be of the form
180 .Bd -ragged -offset indent -compact
181 .Ar hostname ether_addr
183 .Op Cm blackhole No \&| Cm reject
184 .Op Cm pub Op Cm only
187 with argument meanings as given above.
188 Leading whitespace and empty lines are ignored.
191 character will mark the rest of the line as a comment.