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33 .Nd address resolution display and control
36 .Op Fl -libxo Ar options
41 .Op Fl -libxo Ar options
52 .Fl s Ar hostname ether_addr
54 .Op Cm blackhole No \&| Cm reject
57 .Fl S Ar hostname ether_addr
59 .Op Cm blackhole No \&| Cm reject
66 utility displays and modifies the Internet-to-Ethernet address translation
67 tables used by the address resolution protocol
69 With no flags, the program displays the current
73 The host may be specified by name or by number,
74 using Internet dot notation.
77 .Bl -tag -width indent
81 in a selection of different human and machine readable formats.
84 for details on command line arguments.
86 The program displays or, if it is used with the
88 flag, deletes all of the current
92 A super-user may delete an entry for the host called
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.
146 keyword is specified the entry will be marked so that traffic to
147 the host will be discarded and the sender will be notified the
151 keyword is similar in that traffic is discarded but the sender is
153 These can be used to block external traffic to a host without
155 .It Fl S Ar hostname ether_addr
160 entry for this host will be deleted first.
164 to be read and multiple entries to be set in the
168 in the file should be of the form
170 .Bd -ragged -offset indent -compact
171 .Ar hostname ether_addr
173 .Op Cm blackhole No \&| Cm reject
177 with argument meanings as given above.
178 Leading whitespace and empty lines are ignored.
181 character will mark the rest of the line as a comment.
186 .Xr xo_parse_args 3 ,