]>
Commit | Line | Data |
---|---|---|
9f3d938c TL |
1 | .\" dhcpd.conf.5 |
2 | .\" | |
3 | .\" Copyright (c) 1997 The Internet Software Consortium. | |
4 | .\" All rights reserved. | |
5 | .\" | |
6 | .\" Redistribution and use in source and binary forms, with or without | |
7 | .\" modification, are permitted provided that the following conditions | |
8 | .\" are met: | |
9 | .\" | |
10 | .\" 1. Redistributions of source code must retain the above copyright | |
11 | .\" notice, this list of conditions and the following disclaimer. | |
12 | .\" 2. Redistributions in binary form must reproduce the above copyright | |
13 | .\" notice, this list of conditions and the following disclaimer in the | |
14 | .\" documentation and/or other materials provided with the distribution. | |
15 | .\" 3. Neither the name of The Internet Software Consortium nor the names | |
16 | .\" of its contributors may be used to endorse or promote products derived | |
17 | .\" from this software without specific prior written permission. | |
18 | .\" | |
19 | .\" THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND | |
20 | .\" CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, | |
21 | .\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
22 | .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
23 | .\" DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR | |
24 | .\" CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
25 | .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
26 | .\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF | |
27 | .\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | |
28 | .\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
29 | .\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT | |
30 | .\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | .\" SUCH DAMAGE. | |
32 | .\" | |
33 | .\" This software has been written for the Internet Software Consortium | |
34 | .\" by Ted Lemon <mellon@fugue.com> in cooperation with Vixie | |
35 | .\" Enterprises. To learn more about the Internet Software Consortium, | |
36 | .\" see ``http://www.isc.org/isc''. To learn more about Vixie | |
37 | .\" Enterprises, see ``http://www.vix.com''. | |
38 | .TH dhcpd.leases 5 | |
39 | .SH NAME | |
40 | dhcpd.leases - DHCP client lease database | |
41 | .SH DESCRIPTION | |
42 | The Internet Software Consortium DHCP Server keeps a persistent | |
43 | database of leases that it has assigned. This database is a free-form | |
44 | ASCII file containing one valid declaration per lease. If more than | |
45 | one declaration appears for a given lease, the last one in the file is | |
46 | used. The file is written as a log, so this is not an unusual | |
47 | occurrance. | |
48 | .PP | |
49 | When dhcpd is first installed, there is no lease database. However, | |
50 | dhcpd requires that a lease database be present before it will start. | |
51 | To make the initial lease database, just create an empty file called | |
52 | DBDIR/dhcpd.leases. | |
53 | .PP | |
54 | In order to prevent the lease database from growing without bound, the | |
55 | file is rewritten from time to time. First, a temporary lease | |
56 | database is created and all known leases are dumped to it. Then, the | |
57 | old lease database is renamed DBDIR/dhcpd.leases~. Finally, the | |
58 | newly written lease database is moved into place. | |
59 | .PP | |
60 | There is a window of vulnerability where if the dhcpd process is | |
61 | killed or the system crashes after the old lease database has been | |
62 | renamed but before the new one has been moved into place, there will | |
63 | be no DBDIR/dhcpd.leases. In this case, dhcpd will refuse to start, | |
64 | and will require manual intervention. \fBDO NOT\fR simply create a | |
65 | new lease file when this happens - if you do, you will lose all your | |
66 | old bindings, and chaos will ensue. Instead, rename | |
67 | DBDIR/dhcpd.leases~ to DBDIR/dhcpd.leases, restoring the old, valid | |
68 | lease file, and then start dhcpd. This guarantees that a valid lease | |
69 | file will be restored. | |
70 | .SH FORMAT | |
71 | The format of the lease declarations is not currently documented. | |
72 | .SH FILES | |
73 | .B DBDIR/dhcpd.leases | |
74 | .SH SEE ALSO | |
75 | dhcpd(8), dhcp-options(5), dhcpd.conf(5), RFC2132, RFC2131. | |
76 | .SH AUTHOR | |
77 | .B dhcpd(8) | |
78 | was written by Ted Lemon <mellon@vix.com> | |
79 | under a contract with Vixie Labs. Funding | |
80 | for this project was provided by the Internet Software Corporation. | |
81 | Information about the Internet Software Consortium can be found at | |
82 | .B http://www.isc.org/isc. |