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  man pages->Tru64 Unix man pages -> dhcpconf (8)              



NAME    [Toc]    [Back]

       dhcpconf - Controller for DHCP client configuration

SYNOPSIS    [Toc]    [Back]

       /usr/sbin/dhcpconf  [-d] [-f] [-s] [-a server_ip] [-w seconds]
 interface start | drop | release

       /usr/sbin/dhcpconf [interface] dns | domain |  gateways  |
       hostname | nis | routes

OPTIONS    [Toc]    [Back]

       Directs  all  DHCP  protocol  messages  to  the  given  IP
       address.  Currently not implemented.  Starts DHCP only  if
       the  interface  is  down.   Starts the DHCP client daemon,
       joinc, if not already running. This option is  implied  by
       the  start  command.   Instructs  dhcpconf to wait for the
       time specified (if positive) or forever (if negative),  or
       until  the  operation  completes  or fails. This option is
       only relevant on operations which cannot complete  immediately.
  If  the  timer  expires  while the operation is in
       progress, dhcpconf exits with  a  failure  code,  but  the
       operation  continues.  If the user specifies a finite wait
       interval it should, for consistency, be at least equal  to
       the  sum  of the timeout values for exponential backoff in
       the startup file, /etc/join/client.pcy.   This  option  is
       only  relevant  on the start command. When an interface is
       started, joinc sends DHCP discover packets using the exponential
  backoff and retransmission intervals given in the
       /etc/join/client.pcy file. If no reply is received at  the
       end  of  this  cycle, the client replies to the controller
       with failure. When this option is in effect, joinc continues
  trying  to  contact  a DHCP server forever, either by
       retrying the whole backoff cycle or using the last timeout
       value  in  the array. See client.pcy(4) for details.  Puts
       the interface specified under control of DHCP.  The  joinc
       server commences the DHCP on the interface. Fine tuning of
       this process is provided by parameters in the startup file
       /etc/join/client.pcy.  Makes joinc take the interface down
       and transmit a DHCP release message  to  the  DHCP  server
       that the IP address assigned to the interface is no longer
       needed. The server is permitted to reassign the IP address
       to another client.  Tells the client daemon that it should
       relinquish control of the interface. The options  to  drop
       and release the interface are subtly different. Release is
       part of the DHCP protocol; drop is not.  Drop  tells  DHCP
       that  its  services  for  the interface in question are no
       longer required -- DHCP will not try to renew the lease on
       the  IP  address  and if the lease should expire no action
       will be taken. This violates the protocol and is not  recommended,
 except for testing.

DESCRIPTION    [Toc]    [Back]

       The dhcpconf command and its companion joinc implement the
       client side of the Dynamic  Host  Configuration  Protocol,
       DHCP.  The  responsibilities  of  dhcpconf are as follows:
       Control invocation and termination of DHCP on the client's
       hardware interface(s).  Provide a mechanism for rendezvous
       with the transactions of DHCP which are  proceeding  asynchronously
 with respect to the client boot.

       All  invocations of dhcpconf send instructions or requests
       to joinc, which is listening at a well known  port  number
       on  the  Internet Protocol loopback address. Unless the -w
       option is given, dhcpconf expects an immediate reply,  and
       exits  immediately with a success or failure code, depending
 upon the reply received. When the request is one which
       the  client  is  unable  to fulfill immediately, the reply
       acknowledges that the request has been validated and  that
       the  client  will  initiate  the  task  required. With the
       exception of start, which  implicitly  starts  the  client
       daemon, dhcpconf exits with a failure code if joinc is not
       already running. When the -w  option  is  given,  dhcpconf
       waits  for  the  requested  operation  either to complete,
       fail, or wait for the number of seconds specified  in  the
       following argument. When the timer expires, dhcpconf exits
       with a failure code, but the operation  requested  continues.

       The dhcpconf commands are divided into two groups: start,

       release,  and  drop initiate and terminate DHCP control of
       an interface. The remainder request dhcpconf to  configure
       the  host-wide  parameters or service specified, according
       to DHCP supplied data. The latter do not, in general, need
       an  interface  to be specified, except in the circumstance
       that different interfaces receive different configurations
       (See NOTES).

NOTES    [Toc]    [Back]

       When  two  or  more interfaces are configured by DHCP, the
       possibility exists that the  configurations  received  may
       differ.  This  is  the norm for interface specific parameters,
 but for parameters that pertain to  the  host  as  a
       whole,  questions  of interpretation arise. List items, in
       particular, may differ for example, the default  gateways.
       When  configuring  services,  dhcpconf will not merge data
       from different interfaces. Rather only a single  interface
       is  consulted, which, unless given on the command line, is
       the first one in dhcpconf program's internal array,  which
       is configured when the request is made.

RESTRICTIONS    [Toc]    [Back]

       A  cluster member should never be a DHCP client. It should
       always use static addressing.

       If a cluster is to support a DHCP server, there  can  only
       be  one  DHCP  server  for all the cluster members using a
       common database with failover.

       DHCP client is not supported on dataless clients.

EXIT STATUS    [Toc]    [Back]

       Exit codes are as follows: Success.  DHCP was not successful.
 The DHCP client daemon may not be running, the interface
 might have failed to configure,  or  no  satisfactory
       DHCP responses were received.  Bad arguments.  A timer was
       set (with -w) and the interface had not configured  before
       it  expired.   Can only be run as root.  Some system error
       (should never occur)

SEE ALSO    [Toc]    [Back]

       Commands: dhcpparm(8), joinc(8), showdhc(8), shleases(8)

       Files: client.pcy(4)

       Information: DHCP(7)

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