System Administration Commands                       in.dhcpd(1M)

NAME
     in.dhcpd - Dynamic Host Configuration Protocol server

SYNOPSIS
     /usr/lib/inet/in.dhcpd [-denv] [-h  relay_hops]  [-i  inter-
     face,   ...]  [-l  syslog_local_facility]  [-b  automatic  |
     manual] [-o DHCP_offer_time] [-t dhcptab_rescan_interval]

     /usr/lib/inet/in.dhcpd  [-dv]  [-h  relay_hops]  [-i  inter-
     face,...]  [-l  syslog_local_facility] -r IP_address | host-
     name, ...

DESCRIPTION
     in.dhcpd is a daemon that responds to  Dynamic  Host  Confi-
     guration  Protocol  (DHCP)  requests and optionally to BOOTP
     protocol requests. The daemon forks a copy  of  itself  that
     runs  as  a  background process. It must be run as root. The
     daemon has two run modes, DHCP server (with  optional  BOOTP
     compatibility mode) and BOOTP relay agent mode.

     The first line  in  the  SYNOPSIS  section  illustrates  the
     options  available in the DHCP/BOOTP server mode. The second
     line in the SYNOPSIS section illustrates the options  avail-
     able when the daemon is run in BOOTP relay agent mode.

     The DHCP and BOOTP protocols are used to provide  configura-
     tion parameters to Internet hosts. Client machines are allo-
     cated their IP addresses as well as other host configuration
     parameters through this mechanism.

     The DHCP/BOOTP daemon manages two types of DHCP data tables:
     the dhcptab configuration table and the DHCP network tables.

     See dhcptab(4) regarding the dhcptab configuration table and
     dhcp_network(4) regarding the DHCP network tables.

     The dhcptab  contains  macro  definitions  defined  using  a
     termcap-like  syntax which permits network administrators to
     define  groups  of  DHCP  configuration  parameters  to   be
     returned  to  clients.  However,  a DHCP/BOOTP server always
     returns hostname, network broadcast address, network  subnet
     mask,  and  IP maximum transfer unit (MTU) if requested by a
     client attached to the same network as the  server  machine.
     If  those options have not been explicitly configured in the
     dhcptab, in.dhcpd returns reasonable default values.

     The dhcptab is read at startup, upon  receipt  of  a  SIGHUP
     signal,  or  periodically  as  specified by the -t option. A
     SIGHUP (sent using the command svcadm refresh  network/dhcp-
     server)  causes  the DHCP/BOOTP daemon to reread the dhcptab
     within an interval from 0-60 seconds (depending on where the
     DHCP  daemon  is  in  its  polling cycle). For busy servers,
     users should run svcadm restart network/dhcp-server to force
     the dhcptab to be reread.

     The DHCP network tables contain mappings of client  identif-
     iers  to IP addresses. These tables are named after the net-
     work they support and the datastore used to maintain them.

     The DHCP network tables  are  consulted  during  runtime.  A
     client  request  received  from  a network for which no DHCP
     network table exists is ignored.

     This command  may  change  in  future  releases  of  Solaris
     software.  Scripts,  programs,  or  procedures that use this
     command might need modification  when  upgrading  to  future
     Solaris  software releases.The command line options provided
     with the in.dhcpd daemon are used only for the current  ses-
     sion,  and  include  only some of the server options you can
     set. The dhcpsvc.conf(4) contains  all  the  server  default
     settings,  and can be modified by using the dhcpmgr utility.
     See dhcpsvc.conf(4) for more details.

OPTIONS
     The following options are supported:

     -b  automatic | manual

         This option enables BOOTP compatibility  mode,  allowing
         the DHCP server to respond to BOOTP clients.  The option
         argument  specifies  whether  the  DHCP  server   should
         automatically  allocate  permanent lease IP addresses to
         requesting  BOOTP  clients  if  the  clients   are   not
         registered  in  the  DHCP  network tables (automatic) or
         respond only to BOOTP clients  who  have  been  manually
         registered  in  the  DHCP network tables ( manual). This
         option only affects DHCP server mode.



     -d

         Debugging mode. The daemon remains as a foreground  pro-
         cess, and displays verbose messages as it processes DHCP
         and/or BOOTP datagrams. Messages are  displayed  on  the
         current TTY.  This option can be used in both DHCP/BOOTP
         server mode and BOOTP relay agent mode.



     -h relay_hops

         Specifies the maximum number of relay  agent  hops  that
         can   occur  before  the  daemon  drops  the  DHCP/BOOTP
         datagram. The default number of relay agent hops  is  4.
         This  option  affects  both  DHCP/BOOTP  server mode and
         BOOTP relay agent mode.



     -i interface, ...

         Selects the network interfaces that  the  daemon  should
         monitor  for  DHCP/BOOTP  datagrams.  The daemon ignores
         DHCP/BOOTP datagrams on network interfaces not specified
         in  this  list.  This  option is only useful on machines
         that have multiple network interfaces. If this option is
         not  specified,  then  the daemon listens for DHCP/BOOTP
         datagrams on all network interfaces. The option argument
         consists  of  a comma-separated list of interface names.
         It affects both DHCP/BOOTP server and BOOTP relay  agent
         run modes.



     -l syslog_local_facility

         The presence of this option turns on transaction logging
         for  the  DHCP  server  or  BOOTP relay agent. The value
         specifies the syslog local facility (an integer  from  0
         to  7  inclusive) the DHCP daemon should use for tagging
         the transactions. Using a  facility  separate  from  the
         LOG_DAEMON  facility allows the network administrator to
         capture these transactions separately  from  other  DHCP
         daemon  events  for such purposes as generating transac-
         tion reports. See syslog(3C), for  details  about  local
         facilities.  Transactions are logged using a record with
         9 space-separated fields as follows:

             1.  Protocol:


                   Relay mode:     "BOOTP"
                   Server mode:    "BOOTP" or "DHCP" based upon client
                                        type.



             2.  Type:


                 Relay mode:     "RELAY-CLNT", "RELAY-SRVR"
                 Server mode:    "ASSIGN", "EXTEND", "RELEASE",
                                     "DECLINE", "INFORM", "NAK" "ICMP-ECHO."



             3.  Transaction time: absolute time in seconds (unix
                 time)


             4.  Lease time:

                 Relay mode:     Always 0.
                 Server mode:    0 for ICMP-ECHO events, absolute time in
                                     seconds (unix time)  otherwise



             5.  Source IP address: Dotted Internet form


                 Relay mode:     Relay interface IP on RELAY-CLNT,
                                        INADDR_ANY on RELAY-SRVR.
                 Server mode:    Client IP.


             6.  Destination IP address: Dotted Internet form


                 Relay mode:     Client IP on RELAY-CLNT, Server IP on
                                                           RELAY-SRVR.
                 Server mode:    Server IP.


             7.  Client Identifier: Hex representation (0-9, A-F)


                 Relay mode:     MAC address
                 Server mode:    BOOTP - MAC address; DHCP - client id


             8.  Vendor Class identifier (white  space  converted
                 to                        periods (.)).


                 Relay mode:     Always "N/A"
                 Server mode:    Vendor class ID tokenized by
                                        converting white space characters
                                        to periods (.)


             9.  MAC address: Hex representation (0-9, A-F)


                 Relay mode:     MAC address
                 Server mode:    MAC address


         The format of this record is subject to  change  between
         releases.

         Transactions are logged to the console if daemon  is  in
         debug mode (-d).

         Logging transactions impact daemon performance.

         It is suggested that you periodically  rotate  the  DHCP
         transaction  log  file  to keep it from growing until it
         fills the filesystem. This can  be  done  in  a  fashion
         similar  to that used for the general system message log
         /var/adm/messages and is  best  accomplished  using  the
         facilities provided by logadm(1M).



     -n

         Disable automatic duplicate IP address  detection.  When
         this  option  is  specified,  the  DHCP  server does not
         attempt to verify that an IP  address  it  is  about  to
         offer  a  client  is  not  in  use. By default, the DHCP
         server pings an IP  address  before  offering  it  to  a
         DHCP/BOOTP  client, to verify that the address is not in
         use by another machine.



     -o DHCP_offer_time

         Specifies the number of seconds the DHCP  server  should
         cache  the  offers  it  has extended to discovering DHCP
         clients. The default setting is 10 seconds. On slow net-
         work  media,  this  value can be increased to compensate
         for slow network performance. This option  affects  only
         DHCP server mode.



     -r IP_address | hostname, ...

         This option enables BOOTP relay agent mode.  The  option
         argument   specifies   a   comma-separated  list  of  IP
         addresses or hostnames of DHCP or BOOTP servers to which
         the  relay  agent is to forward BOOTP requests. When the
         daemon is started in this  mode,  any  DHCP  tables  are
         ignored,  and  the  daemon  simply acts as a BOOTP relay
         agent.

         A BOOTP relay agent listens to UDP port 68, and forwards
         BOOTP  request  packets  received  on  this  port to the
         destinations specified on the command line. It  supports
         the  BROADCAST flag described in RFC 1542. A BOOTP relay
         agent can run on any machine that has knowledge of local
         routers,  and thus does not have to be an Internet gate-
         way machine.

         Note that the proper entries must be made  to  the  net-
         masks  database  so that the DHCP server being served by
         the BOOTP relay agents can identify the subnet  mask  of
         the foreign BOOTP/DHCP client's network. See netmasks(4)
         for the format and use of this database.



     -t dhcptab_rescan_interval

         Specifies the interval in minutes that the  DHCP  server
         should  use  to  schedule the automatic rereading of the
         dhcptab  information.  Typically,  you  would  use  this
         option if the changes to the dhcptab are relatively fre-
         quent. Once the contents of the dhcptab have stabilized,
         you  can  turn  off this option to avoid needless reini-
         tialization of the server.



     -v

         Verbose mode. The daemon displays more messages than  in
         the default mode. Note that verbose mode can reduce dae-
         mon efficiency due to the time  taken  to  display  mes-
         sages.  Messages are displayed to the current TTY if the
         debugging option is used; otherwise, messages are logged
         to the syslogd facility. This option can be used in both
         DHCP/BOOTP server mode and BOOTP relay agent mode.



EXAMPLES
     Example 1: Starting a DHCP  Server  in  BOOTP  Compatibility
     Mode

     The following command starts a DHCP server in BOOTP compati-
     bility mode, permitting the server to automatically allocate
     permanent IP  addresses  to  BOOTP  clients  which  are  not
     registered in the server's table; limits the server's atten-
     tion to incoming datagrams on network devices le2  and  tr0;
     drops  BOOTP  packets  whose hop count exceeds 2; configures
     the DHCP  server  to  cache  extended  DHCP  offers  for  15
     seconds;  and  schedules  dhcptab  rescans to occur every 10
     minutes:


     # in.dhcpd -i le2,tr0 -h 2 -o 15 -t 10 -b automatic

     Example 2: Starting the Daemon in BOOTP Relay Agent Mode

     The following command starts the daemon in BOOTP relay agent
     mode,  registering  the  hosts  bladerunner  and 10.0.0.5 as
     relay  destinations,  with  debugging  and   verbose   modes
     enabled, and drops BOOTP packets whose hop count exceeds 5:

     # in.dhcpd -d -v -h 5 -r bladerunner,10.0.0.5

FILES
     /etc/inet/dhcpsvc.conf


     /etc/init/hosts



     /usr/lib/inet/dhcp/nsu/rfc2136.so.1



ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWdhcsu                   |
    |_____________________________|_____________________________|
    | Interface Stability         | Evolving                    |
    |_____________________________|_____________________________|


SEE ALSO
     svcs(1),  cron(1M),  dhcpmgr(1M),  dhtadm(1M),  inetadm(1M),
     inetd(1M),  logadm(1M), pntadm(1M), svcadm(1M), syslogd(1M),
     syslog(3C),  dhcpsvc.conf(4),  dhcp_network(4),  dhcptab(4),
     ethers(4),  hosts(4),  netmasks(4), nsswitch.conf(4), attri-
     butes(5), dhcp(5), smf(5)

     System Administration Guide: IP Services

     Alexander, S., and R. Droms, DHCP Options and  BOOTP  Vendor
     Extensions,  RFC  2132,  Silicon  Graphics,  Inc.,  Bucknell
     University, March 1997.

     Droms, R., Interoperation Between DHCP and BOOTP, RFC  1534,
     Bucknell University, October 1993.

     Droms, R., Dynamic Host Configuration  Protocol,  RFC  2131,
     Bucknell University, March 1997.

     Wimer, W., Clarifications and Extensions for  the  Bootstrap
     Protocol,  RFC  1542,  Carnegie  Mellon  University, October
     1993.

NOTES
     The in.dhcpd service is managed by  the  service  management
     facility, smf(5), under the service identifier:

     svc:/network/dhcp-server

     Administrative actions on this service,  such  as  enabling,
     disabling,  or  requesting  restart,  can be performed using
     svcadm(1M). Responsibility  for  initiating  and  restarting
     this  service  is delegated to inetd(1M). Use inetadm(1M) to
     make configuration changes and to view configuration  infor-
     mation for this service. The service's status can be queried
     using the svcs(1) command.