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



NAME    [Toc]    [Back]

       jdbmod  -  Adds,  modifies,  or  deletes  data in the DHCP
       dynamic databases.

SYNOPSIS    [Toc]    [Back]

       /usr/sbin/jdbmod [-d] [-e] [-f character] [-i] [-l  |  -n]
       [-o] [-w] filename...

OPTIONS    [Toc]    [Back]

       Loads  the  data  of  a  particular record even though the
       lease has expired.   The  default  is  not  to  load  such
       records.   Use  this option with care; the server may have
       released the expired addresses to a new client  since  the
       data  was  dumped.   Deletes  the  records  whose keys are
       implied by the input file(s).   The  key  fields  are  the
       hardware type and address and the subnet containing the IP
       address.  Uses character  as  the  field  separator.   The
       default  is the pipe (|) character.  Allows an existing IP
       address assignment  to  be  overridden.   By  default,  an
       attempt  to assign an IP address will fail if that address
       already exists and is bound to a different  client.   This
       differs  from the -w option, which controls whether a preexisting
 MAC-address/client-id  pairing  may  be  updated.
       Loads  lease  information  only.   Do not load names.  The
       default is to load both.   Loads  name  information  only.
       Loads  only records owned by this server.  Allows existing
       records to be overwritten.  The default mode is to  forbid
       the update if the record already exists in the database.

              The jbdmod command keys its data entry from the MAC
              address and subnet IP address tuple  replacing  the
              record  in  overwrite mode if it already exists, or
              adding the record if not. It  also  checks  whether
              the  IP  address  has already been taken by another

DESCRIPTION    [Toc]    [Back]

       The jdbmod command modifies the databases used by joind to
       store  information on client IP address leases and dynamic
       names. The jdbmod command allows the user to  load  preassigned
  hardware-IP address combinations for those clients
       requiring infinite leases.  Each record to  be  loaded  is
       terminated by a newline, and the fields within each record
       delimited by default with the pipe (|) character, although
       this may be changed with the -f command line option.  Date
       fields may be expressed either  in  Universal  Coordinated
       Time  (UCT),  which  is  the number of seconds since 00:00
       01/01/1970 GMT, or in a variety  of  formats  more  easily
       understood by liveware (for example, Mon Jan 09 1995 10:00
       and 01/09/1995 10:00:00).

       The fields within the data file(s) to  be  loaded  are  as
       follows:  This is the identifier which uniquely identifies
       the client.  It may be the  client's  MAC  address  or  an
       opaque  object,  uninterpreted  by  the JOIN software.  If
       non-zero, then the client id is the  MAC  address  of  the
       client  corresponding  to  this  type.   If zero, then the
       client id may be any byte array which serves  uniquely  to
       identify  the  client.   The  length  of the identifier in
       8-bit bytes. Note that if the client id corresponds  to  a
       MAC   address  then  the  value  of  this  field  must  be
       consistent with the length implied by client id type.  But
       in  the  more  general  case, it may be needed in order to
       determine whether the client id is to be interpreted as  a
       literal  or as a decimal or hexadecimal encoding of a byte
       string.  The IP address assigned to the client.   If  this
       value is null or it means "none". This is possible
       if jdbmod is being used to load  client  id/name  combinations
  in  advance of the client being bound to a specific
       IP address. This has the effect of  reserving  a  name  as
       belonging  to  that  client.  The time at which this lease
       began.  A value of zero (or null) is taken  to  mean  now.
       The  time  at  which  this  lease will expire.  A negative
       value is taken to mean no expiration. This  is  stored  in
       the  database  as the maximum positive signed 32 bit value
       which translates to Jan 18 19:14:07  2038.   The  time  at
       which  this  lease  may  be renewed. Requests to renew the
       lease prior to this will be answered by a reply determined
       by  the residual time remaining on the lease until expiration.
 After this time has passed, the client will  receive
       an  entirely new lease whose duration is determined by the
       bootptab database.  Time when the client last acquired  or
       renewed  this  lease.   Unless this value is known from an
       invocation of jdbdump it is best to set it to -1 or  null,
       which  has  the  conventional  significance  of  now.   IP
       address of server "owning" the lease.  If  this  value  is
       null  or it means that the lease will become owned
       by this server.  The client's  name  (without  the  domain
       name).  This  name must obey the rules set forth in RFC952
       as amended by RFC1123. It must be accompanied by  a  valid
       domain  and  it  is  converted  to  lowercase before being
       stored in the database.  The client's domain (without  the
       leaf  name).  This domain must obey the rules set forth in
       RFC952 as amended by RFC1123 and  it  must  not  have  any
       trailing  period. The name domain combination is stored in
       the database as a single entity after being  converted  to

NOTES    [Toc]    [Back]

       The  jdbmod  command  loads name-address bindings into the
       JOIN databases.  It does not modify existing name services
       (NIS, NIS+, or BIND/DNS).  The intent is exactly contrary;
       the name and address bindings should have been  determined
       from  an  authoritative source, either the name service in
       use or a previous backup of the database made by  jdbdump.

       The  JOIN database does not permit a client, as identified
       by the client id field, to have a lease on more  than  one
       IP  address on the same network.  But, a client is permitted
 to have leases on IP addresses on different  networks.
       If  you  attempt to load a lease binding a client to an IP
       address, jdbmod first checks  that  the  client  holds  no
       other  outstanding lease on the same network.  If it does,
       the binding is rejected. The -w option allows this  behavior
  to  be overridden.  The binding of the old IP address
       to the client is dissolved and  is  replaced  by  the  new

       The  behavior of the -i option is different. An attempt to
       bind an IP address to a client is forbidden if the address
       is  already  bound  to  a different client.  The -i option
       explicitly permits this behavior, dissolving  the  binding
       of the old IP address and rebinding to the new client.  In
       the most general case, if you are sure that the  data  you
       are loading is authoritative, both options are needed.

RESTRICTIONS    [Toc]    [Back]

       Because  the  database  used by join does not support multiuser
 concurrency, applications that write to it lock the
       entire  database.  This means that you cannot use the jdbmod
 command while the joind daemon is running.   The  converse
 is also true.

       The  jdbmod  command  keys  its  data  entry  from the MAC
       address/ subnet IP address tuple, replacing the record  in
       overwrite  mode if it already exists, or adding the record
       if it does not.  However, it does not  check  whether  the
       resulting  IP  address  has  already been taken by another
       client.  Before loading a file, you must ensure that no IP
       address conflicts exist either internal to the file itself
       or to the existing database.

FILES    [Toc]    [Back]

       Commands: jdbdump(8), joind(8)

       Files: bootptab(4)

[ Back ]
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