1in.dhcpd(1M)            System Administration Commands            in.dhcpd(1M)
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3
4

NAME

6       in.dhcpd - Dynamic Host Configuration Protocol server
7

SYNOPSIS

9       /usr/lib/inet/in.dhcpd  [-denv] [-h relay_hops] [-i interface, ...]
10        [-l syslog_local_facility] [-b automatic | manual]
11        [-o DHCP_offer_time] [-t dhcptab_rescan_interval]
12
13
14       /usr/lib/inet/in.dhcpd  [-dv] [-h relay_hops] [-i interface,]...
15        [-l syslog_local_facility] -r IP_address | hostname, ...
16
17

DESCRIPTION

19       in.dhcpd is a daemon that responds to Dynamic Host Configuration Proto‐
20       col (DHCP) requests and optionally to BOOTP protocol requests. The dae‐
21       mon  forks  a copy of itself that runs as a background process. It must
22       be run as root. The  daemon  has  two  run  modes,  DHCP  server  (with
23       optional BOOTP compatibility mode) and BOOTP relay agent mode.
24
25
26       The  first  line in the SYNOPSIS section illustrates the options avail‐
27       able in the DHCP/BOOTP server mode. The second  line  in  the  SYNOPSIS
28       section  illustrates  the  options  available when the daemon is run in
29       BOOTP relay agent mode.
30
31
32       The DHCP and BOOTP protocols are used to provide configuration  parame‐
33       ters  to  Internet  hosts.  Client  machines  are  allocated  their  IP
34       addresses as well as other host configuration parameters  through  this
35       mechanism.
36
37
38       The  DHCP/BOOTP  daemon  manages  two  types  of  DHCP data tables: the
39       dhcptab configuration table and the DHCP network tables.
40
41
42       See dhcptab(4) regarding the dhcptab configuration table and  dhcp_net‐
43       work(4) regarding the DHCP network tables.
44
45
46       The  dhcptab  contains  macro  definitions defined using a termcap-like
47       syntax which permits network administrators to define  groups  of  DHCP
48       configuration   parameters  to  be  returned  to  clients.  However,  a
49       DHCP/BOOTP server always returns hostname, network  broadcast  address,
50       network subnet mask, and IP maximum transfer unit (MTU) if requested by
51       a client attached to the same network as the server machine.  If  those
52       options  have  not  been explicitly configured in the dhcptab, in.dhcpd
53       returns reasonable default values.
54
55
56       The dhcptab is read at startup, upon receipt of  a  SIGHUP  signal,  or
57       periodically  as  specified  by the -t option. A SIGHUP (sent using the
58       command svcadm refresh network/dhcp-server) causes the DHCP/BOOTP  dae‐
59       mon to reread the dhcptab within an interval from 0-60 seconds (depend‐
60       ing on where the DHCP  daemon  is  in  its  polling  cycle).  For  busy
61       servers,  users  should run svcadm restart network/dhcp-server to force
62       the dhcptab to be reread.
63
64
65       The DHCP network tables contain mappings of client  identifiers  to  IP
66       addresses.  These  tables  are named after the network they support and
67       the datastore used to maintain them.
68
69
70       The DHCP network tables are consulted during runtime. A client  request
71       received  from  a  network  for  which  no DHCP network table exists is
72       ignored.
73
74
75       This command  may  change  in  future  releases  of  Solaris  software.
76       Scripts, programs, or procedures that use this command might need modi‐
77       fication when upgrading to future Solaris software releases.The command
78       line  options  provided  with the in.dhcpd daemon are used only for the
79       current session, and include only some of the server  options  you  can
80       set.  The dhcpsvc.conf(4) contains all the server default settings, and
81       can be modified by using the dhcpmgr utility. See  dhcpsvc.conf(4)  for
82       more details.
83

OPTIONS

85       The following options are supported:
86
87       -b  automatic | manual
88
89           This  option  enables  BOOTP  compatibility mode, allowing the DHCP
90           server to respond to BOOTP clients. The option  argument  specifies
91           whether  the  DHCP  server  should automatically allocate permanent
92           lease IP addresses to requesting BOOTP clients if the  clients  are
93           not  registered  in  the DHCP network tables (automatic) or respond
94           only to BOOTP clients who have been manually registered in the DHCP
95           network  tables  (  manual).  This  option only affects DHCP server
96           mode.
97
98
99       -d
100
101           Debugging mode. The daemon remains as  a  foreground  process,  and
102           displays  verbose  messages as it processes DHCP and/or BOOTP data‐
103           grams. Messages are displayed on the current TTY. This  option  can
104           be used in both DHCP/BOOTP server mode and BOOTP relay agent mode.
105
106
107       -h relay_hops
108
109           Specifies  the  maximum  number  of relay agent hops that can occur
110           before the daemon drops the DHCP/BOOTP datagram. The default number
111           of  relay  agent  hops  is  4.  This option affects both DHCP/BOOTP
112           server mode and BOOTP relay agent mode.
113
114
115       -i interface, ...
116
117           Selects the network interfaces that the daemon should  monitor  for
118           DHCP/BOOTP  datagrams.  The  daemon ignores DHCP/BOOTP datagrams on
119           network interfaces not specified in this list. This option is  only
120           useful  on  machines that have multiple network interfaces. If this
121           option is not specified, then the  daemon  listens  for  DHCP/BOOTP
122           datagrams  on  all network interfaces. The option argument consists
123           of a comma-separated list  of  interface  names.  It  affects  both
124           DHCP/BOOTP server and BOOTP relay agent run modes.
125
126
127       -l syslog_local_facility
128
129           The  presence  of  this option turns on transaction logging for the
130           DHCP server or BOOTP relay agent. The value  specifies  the  syslog
131           local  facility  (an integer from 0 to 7 inclusive) the DHCP daemon
132           should use for tagging the transactions. Using a facility  separate
133           from  the  LOG_DAEMON  facility allows the network administrator to
134           capture these transactions separately from other DHCP daemon events
135           for  such  purposes  as  generating  transaction  reports. See sys‐
136           log(3C), for  details  about  local  facilities.  Transactions  are
137           logged using a record with 9 space-separated fields as follows:
138
139               1.     Protocol:
140
141                          Relay mode:     "BOOTP"
142                          Server mode:    "BOOTP" or "DHCP" based upon client
143                                               type.
144
145
146
147               2.     Type:
148
149                        Relay mode:     "RELAY-CLNT", "RELAY-SRVR"
150                        Server mode:    "ASSIGN", "EXTEND", "RELEASE",
151                                            "DECLINE", "INFORM", "NAK" "ICMP-ECHO."
152
153
154
155               3.     Transaction time: absolute time in seconds (unix time)
156
157               4.     Lease time:
158
159                        Relay mode:     Always 0.
160                        Server mode:    0 for ICMP-ECHO events, absolute time in
161                                            seconds (unix time)  otherwise
162
163
164
165               5.     Source IP address: Dotted Internet form
166
167               Relay mode:     Relay interface IP on RELAY-CLNT,  INADDR_ANY on RELAY-SRVR. Server mode:    Client IP.
168
169
170               6.     Destination IP address: Dotted Internet form
171
172               Relay mode:     Client IP on RELAY-CLNT, Server IP on RELAY-SRVR. Server mode:    Server IP.
173
174
175               7.     Client Identifier: Hex representation (0-9, A-F)
176
177               Relay mode:     MAC address                          Server mode:    BOOTP - MAC address; DHCP - client id
178
179
180               8.     Vendor   Class  identifier  (white  space  converted  to
181                      periods (.)).
182
183               Relay mode:     Always "N/A" Server mode:    Vendor class ID tokenized by  converting white space characters  to periods (.)
184
185
186               9.     MAC address: Hex representation (0-9, A-F)
187
188               Relay mode:     MAC address Server mode:    MAC address
189
190           The format of this record is subject to change between releases.
191
192           Transactions are logged to the console if daemon is in  debug  mode
193           (-d).
194
195           Logging transactions impact daemon performance.
196
197           It  is  suggested that you periodically rotate the DHCP transaction
198           log file to keep it from growing until  it  fills  the  filesystem.
199           This  can be done in a fashion similar to that used for the general
200           system message log /var/adm/messages and is best accomplished using
201           the facilities provided by logadm(1M).
202
203
204       -n
205
206           Disable  automatic duplicate IP address detection. When this option
207           is specified, the DHCP server does not attempt to verify that an IP
208           address  it  is  about to offer a client is not in use. By default,
209           the DHCP server pings  an  IP  address  before  offering  it  to  a
210           DHCP/BOOTP  client,  to  verify  that  the address is not in use by
211           another machine.
212
213
214       -o DHCP_offer_time
215
216           Specifies the number of seconds the DHCP server  should  cache  the
217           offers  it  has  extended  to discovering DHCP clients. The default
218           setting is 10 seconds. On slow network media,  this  value  can  be
219           increased  to  compensate for slow network performance. This option
220           affects only DHCP server mode.
221
222
223       -r IP_address | hostname, ...
224
225           This option enables BOOTP relay agent  mode.  The  option  argument
226           specifies  a  comma-separated  list of IP addresses or hostnames of
227           DHCP or BOOTP servers to which the relay agent is to forward  BOOTP
228           requests.  When the daemon is started in this mode, any DHCP tables
229           are ignored, and the daemon simply acts as a BOOTP relay agent.
230
231           A BOOTP relay agent listens to UDP  port  68,  and  forwards  BOOTP
232           request packets received on this port to the destinations specified
233           on the command line. It supports the BROADCAST  flag  described  in
234           RFC  1542.  A  BOOTP  relay  agent  can run on any machine that has
235           knowledge of local routers, and thus does not have to be an  Inter‐
236           net gateway machine.
237
238           Note  that the proper entries must be made to the netmasks database
239           so that the DHCP server being served by the BOOTP relay agents  can
240           identify  the  subnet  mask of the foreign BOOTP/DHCP client's net‐
241           work. See netmasks(4) for the format and use of this database.
242
243
244       -t dhcptab_rescan_interval
245
246           Specifies the interval in minutes that the DHCP server  should  use
247           to  schedule  the  automatic  rereading of the dhcptab information.
248           Typically, you would use this option if the changes to the  dhcptab
249           are relatively frequent. Once the contents of the dhcptab have sta‐
250           bilized, you can turn off this option to avoid needless  reinitial‐
251           ization of the server.
252
253
254       -v
255
256           Verbose mode. The daemon displays more messages than in the default
257           mode. Note that verbose mode can reduce daemon  efficiency  due  to
258           the  time  taken to display messages. Messages are displayed to the
259           current TTY if the debugging option is  used;  otherwise,  messages
260           are logged to the syslogd facility. This option can be used in both
261           DHCP/BOOTP server mode and BOOTP relay agent mode.
262
263

EXAMPLES

265       Example 1 Starting a DHCP Server in BOOTP Compatibility Mode
266
267
268       The following command starts a DHCP server in BOOTP compatibility mode,
269       permitting  the server to automatically allocate permanent IP addresses
270       to BOOTP clients which are not registered in the server's table; limits
271       the server's attention to incoming datagrams on network devices le2 and
272       tr0; drops BOOTP packets whose hop count exceeds 2; configures the DHCP
273       server  to  cache  extended  DHCP  offers for 15 seconds; and schedules
274       dhcptab rescans to occur every 10 minutes:
275
276
277         # in.dhcpd -i le2,tr0 -h 2 -o 15 -t 10 -b automatic
278
279
280
281       Example 2 Starting the Daemon in BOOTP Relay Agent Mode
282
283
284       The following command starts the daemon in BOOTP relay agent mode, reg‐
285       istering the hosts bladerunner and 10.0.0.5 as relay destinations, with
286       debugging and verbose modes enabled, and drops BOOTP packets whose  hop
287       count exceeds 5:
288
289
290         # in.dhcpd -d -v -h 5 -r bladerunner,10.0.0.5
291
292
293

FILES

295       /etc/inet/dhcpsvc.conf
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297
298
299
300       /etc/init/hosts
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302
303
304
305       /usr/lib/inet/dhcp/nsu/rfc2136.so.1
306
307
308
309

ATTRIBUTES

311       See attributes(5) for descriptions of the following attributes:
312
313
314
315
316       ┌─────────────────────────────┬─────────────────────────────┐
317       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
318       ├─────────────────────────────┼─────────────────────────────┤
319       │Availability                 │SUNWdhcsu                    │
320       ├─────────────────────────────┼─────────────────────────────┤
321       │Interface Stability          │Evolving                     │
322       └─────────────────────────────┴─────────────────────────────┘
323

SEE ALSO

325       svcs(1),  cron(1M),  dhcpmgr(1M),  dhtadm(1M),  inetadm(1M), inetd(1M),
326       logadm(1M),   pntadm(1M),    svcadm(1M),    syslogd(1M),    syslog(3C),
327       dhcpsvc.conf(4), dhcp_network(4), dhcptab(4), ethers(4), hosts(4), net‐
328       masks(4), nsswitch.conf(4), attributes(5), dhcp(5), smf(5)
329
330
331
332
333
334       Alexander, S., and R. Droms, DHCP Options and BOOTP Vendor  Extensions,
335       RFC 2132, Silicon Graphics, Inc., Bucknell University, March 1997.
336
337
338       Droms,  R.,  Interoperation  Between DHCP and BOOTP, RFC 1534, Bucknell
339       University, October 1993.
340
341
342       Droms, R., Dynamic Host Configuration Protocol, RFC 2131, Bucknell Uni‐
343       versity, March 1997.
344
345
346       Wimer,  W.,  Clarifications  and Extensions for the Bootstrap Protocol,
347       RFC 1542, Carnegie Mellon University, October 1993.
348

NOTES

350       The in.dhcpd service is managed by  the  service  management  facility,
351       smf(5), under the service identifier:
352
353         svc:/network/dhcp-server
354
355
356
357
358       Administrative actions on this service, such as enabling, disabling, or
359       requesting restart, can be performed using  svcadm(1M).  Responsibility
360       for  initiating  and restarting this service is delegated to inetd(1M).
361       Use inetadm(1M) to make configuration changes and to view configuration
362       information for this service. The service's status can be queried using
363       the svcs(1) command.
364
365
366
367SunOS 5.11                        10 Aug 2004                     in.dhcpd(1M)
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