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33 .Nd address resolution display and control
36 .Op Fl -libxo Ar options
41 .Op Fl -libxo Ar options
53 .Fl s Ar hostname ether_addr
55 .Op Cm blackhole No \&| Cm reject
58 .Fl S Ar hostname ether_addr
60 .Op Cm blackhole No \&| Cm reject
67 utility displays and modifies the Internet-to-Ethernet address translation
68 tables used by the address resolution protocol
70 With no flags, the program displays the current
74 The host may be specified by name or by number,
75 using Internet dot notation.
78 .Bl -tag -width indent
82 in a selection of different human and machine readable formats.
85 for details on command line arguments.
87 The program displays or, if it is used with the
89 flag, deletes all of the current
93 A super-user may delete an entry for the host called
100 keyword is specified, only the
104 for this host will be deleted.
108 flag may be combined with the
110 flag to delete all entries.
111 .It Fl i Ar interface
112 Limit the operation scope to the
116 Applicable only to the following operations:
117 display one, display all, delete all.
119 Show network addresses as numbers (normally
121 attempts to display addresses symbolically).
122 .It Fl s Ar hostname ether_addr
125 entry for the host called
127 with the Ethernet address
129 The Ethernet address is given as six hex bytes separated by colons.
130 The entry will be permanent unless the word
132 is given in the command.
135 is given, the entry will be
137 i.e., this system will
141 responding to requests for
143 even though the host address is not its own.
148 in which case the interfaces on this host will be examined,
149 and if one of them is found to occupy the same subnet, its
150 Ethernet address will be used.
154 keyword is specified the entry will be marked so that traffic to
155 the host will be discarded and the sender will be notified the
159 keyword is similar in that traffic is discarded but the sender is
161 These can be used to block external traffic to a host without
163 .It Fl S Ar hostname ether_addr
168 entry for this host will be deleted first.
172 to be read and multiple entries to be set in the
176 in the file should be of the form
178 .Bd -ragged -offset indent -compact
179 .Ar hostname ether_addr
181 .Op Cm blackhole No \&| Cm reject
185 with argument meanings as given above.
186 Leading whitespace and empty lines are ignored.
189 character will mark the rest of the line as a comment.
194 .Xr xo_parse_args 3 ,