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RedHat 9 (Linux i386) - man page for omshell (redhat section 1)

omshell(1)			     General Commands Manual			       omshell(1)

NAME
       omshell - OMAPI Command Shell

SYNOPSIS
       omshell

DESCRIPTION
       The  OMAPI  Command  Shell, omshell, provides an interactive way to connect to, query, and
       possibly change, the ISC DHCP Server's state via OMAPI, the  Object  Management	API.   By
       using  OMAPI and omshell, you do not have to stop, make changes, and then restart the DHCP
       server, but can make the changes while the server is running.   Omshell provides a way  of
       accessing OMAPI.

       OMAPI  is  simply  a  communications mechanism that allows you to manipulate objects.   In
       order to actually use omshell, you must understand what objects are available and  how  to
       use  them.   Documentation  for	OMAPI  objects	can be found in the documentation for the
       server that provides them - for example, in the dhcpd(1) manual page and  the  dhclient(1)
       manual page.

CONTRIBUTIONS
       This software is free software.	At various times its development has been underwritten by
       various organizations, including the ISC and Vixie Enterprises.	The  development  of  3.0
       has been funded almost entirely by Nominum, Inc.

       At this point development is being shepherded by Ted Lemon, and hosted by the ISC, but the
       future of this project depends on you.  If you have features  you  want,  please  consider
       implementing them.

LOCAL AND REMOTE OBJECTS
       Throughout this document, there are references to local and remote objects.  Local objects
       are ones created in omshell with the new command.  Remote objects are ones on the  server:
       leases,	hosts, and groups that the DHCP server knows about.  Local and remote objects are
       associated together to enable viewing and modification of object  attributes.   Also,  new
       remote objects can be created to match local objects.

OPENING A CONNECTION
       omshell is started from the command line.  Once omshell is started, there are several com-
       mands that can be issued:

       server address
	    where address is the IP address of the DHCP server to connect to.	If  this  is  not
	    specified, the default server is 127.0.0.1 (localhost).

       port number
	    where number is the port that OMAPI listens on.  By default, this is 7911.

       key name secret
	    This  specifies  the TSIG key to use to authenticate the OMAPI transactions.  name is
	    the name of a key defined in dhcpd.conf with the omapi-key statement.  The secret  is
	    the secret generated from dnssec-keygen or another key generation program.

       connect
	    This starts the OMAPI connection to the server as specified by the server statement.

CREATING LOCAL OBJECTS
       Any  object  defined  in OMAPI can be created, queried, and/or modified.  The object types
       available to OMAPI are defined in dhcpd(8) and dhclient.  When using omshell, objects  are
       first  defined  locally, manipulated as desired, and then associated with an object on the
       server.	Only one object can be manipulated at a time.  To create a local object, use

       new object-type
	    object-type is one of group, host, or lease.

       At this point, you now have an object that you can set properties on.  For example,  if	a
       new  lease  object  was	created with new lease, any of a lease's attributes can be set as
       follows:

       set attribute-name = value
	    Attribute names are defined in dhcpd(8) and dhclient(8).  Values should be quoted  if
	    they are strings.  So, to set a lease's IP address, you would do the following:
	     set ip-address = 192.168.4.50

ASSOCIATING LOCAL AND REMOTE OBJECTS
       At this point, you can query the server for information about this lease, by

       open

       Now,  the local lease object you created and set the IP address for is associated with the
       corresponding lease object on the DHCP server.  All of the lease attributes from the  DHCP
       server are now also the attributes on the local object, and will be shown in omshell.

VIEWING A REMOTE OBJECT
       To query a lease of address 192.168.4.50, and find out its attributes, after connecting to
       the server, take the following steps:

       new lease

       This creates a new local lease object.

       set ip-address = 192.168.4.50

       This sets the local object's IP address to be 192.168.4.50

       open

       Now, if a lease with that IP address exists, you will see all  the  information	the  DHCP
       server  has  about that particular lease.  Any data that isn't readily printable text will
       show up in colon-separated hexadecimal values.  In this	example,  output  back	from  the
       server for the entire transaction might look like this:

       > new "lease"
       obj: lease
       > set ip-address = 192.168.4.50
       obj: lease
       ip-address = c0:a8:04:32
       > open
       obj: lease
       ip-address = c0:a8:04:32
       state = 00:00:00:02
       dhcp-client-identifier = 01:00:10:a4:b2:36:2c
       client-hostname = "wendelina"
       subnet = 00:00:00:06
       pool = 00:00:00:07
       hardware-address = 00:10:a4:b2:36:2c
       hardware-type = 00:00:00:01
       ends = dc:d9:0d:3b
       starts = 5c:9f:04:3b
       tstp = 00:00:00:00
       tsfp = 00:00:00:00
       cltt = 00:00:00:00

       As you can see here, the IP address is represented in hexadecimal, as are the starting and
       ending times of the lease.

MODIFYING A REMOTE OBJECT
       Attributes of remote objects are updated by using the set  command  as  before,	and  then
       issuing	an  update  command.   The  set  command sets the attributes on the current local
       object, and the update command pushes those changes out to the server.

       Continuing with the previous example, if a  set	client-hostname  =  "something-else"  was
       issued, followed by an update command, the output would look about like this:

       > set client-hostname = "something-else"
       obj: lease
       ip-address = c0:a8:04:32
       state = 00:00:00:02
       dhcp-client-identifier = 01:00:10:a4:b2:36:2c
       client-hostname = "something-else"
       subnet = 00:00:00:06
       pool = 00:00:00:07
       hardware-address = 00:10:a4:b2:36:2c
       hardware-type = 00:00:00:01
       ends = dc:d9:0d:3b
       starts = 5c:9f:04:3b
       tstp = 00:00:00:00
       tsfp = 00:00:00:00
       cltt = 00:00:00:00
       > update
       obj: lease
       ip-address = c0:a8:04:32
       state = 00:00:00:02
       dhcp-client-identifier = 01:00:10:a4:b2:36:2c
       client-hostname = "something-else"
       subnet = 00:00:00:06
       pool = 00:00:00:07
       hardware-address = 00:10:a4:b2:36:2c
       hardware-type = 00:00:00:01
       ends = dc:d9:0d:3b
       starts = 5c:9f:04:3b
       tstp = 00:00:00:00
       tsfp = 00:00:00:00
       cltt = 00:00:00:00

NEW REMOTE OBJECTS
       New remote objects are created much in the same way that existing server objects are modi-
       fied.  Create a local object using new, set the attributes as you'd wish them to  be,  and
       then create the remote object with the same properties by using

       create

       Now a new object exists on the DHCP server which matches the properties that you gave your
       local object.  Objects created via OMAPI are saved into the dhcpd.leases file.

       For example, if a new host with the IP address of 192.168.4.40  needs  to  be  created  it
       would be done as follows:

       > new host
       obj: host
       > set name = "some-host"
       obj: host
       name = "some-host"
       > set hardware-address = 00:80:c7:84:b1:94
       obj: host
       name = "some-host"
       hardware-address = 00:80:c7:84:b1:94
       > set hardware-type = 1
       obj: host
       name = "some-host"
       hardware-address = 00:80:c7:84:b1:94
       hardware-type = 1
       > set ip-address = 192.168.4.40
       obj: host
       name = "some-host"
       hardware-address = 00:80:c7:84:b1:94
       hardware-type = 1
       ip-address = c0:a8:04:28
       > create
       obj: host
       name = "some-host"
       hardware-address = 00:80:c7:84:b1:94
       hardware-type = 00:00:00:01
       ip-address = c0:a8:04:28
       >

       Your dhcpd.leases file would then have an entry like this in it:

       host some-host {
	 dynamic;
	 hardware ethernet 00:80:c7:84:b1:94;
	 fixed-address 192.168.4.40;
       }

       The  dynamic; line is to denote that this host entry did not come from dhcpd.conf, but was
       created dynamically via OMAPI.

RESETTING ATTRIBUTES
       If you want to remove an attribute from an object, you can do this with the unset command.
       Once  you  have	unset  an attribute, you must use the update command to update the remote
       object.	So, if the host "some-host" from the previous example will not have a  static  IP
       address anymore, the commands in omshell would look like this:

       obj: host
       name = "some-host"
       hardware-address = 00:80:c7:84:b1:94
       hardware-type = 00:00:00:01
       ip-address = c0:a8:04:28
       > unset ip-address
       obj: host
       name = "some-host"
       hardware-address = 00:80:c7:84:b1:94
       hardware-type = 00:00:00:01
       ip-address = <null>
       >

REFRESHING OBJECTS
       A  local  object  may  be  refreshed  with  the current remote object properties using the
       refresh command.  This is useful for object that change periodically, like leases, to  see
       if they have been updated.  This isn't particularly useful for hosts.

DELETING OBJECTS
       Any  remote  object that can be created can also be destroyed.  This is done by creating a
       new local object, setting attributes, associating the local and remote object using  open,
       and  then  using  the  remove command.  If the host "some-host" from before was created in
       error, this could be corrected as follows:

       obj: host
       name = "some-host"
       hardware-address = 00:80:c7:84:b1:94
       hardware-type = 00:00:00:01
       ip-address = c0:a8:04:28
       > remove
       obj: <null>
       >

HELP
       The help command will print out all of the commands available in omshell, with some syntax
       pointers.

SEE ALSO
       dhcpctl(3), omapi(3), dhcpd(8), dhclient(8), dhcpd.conf(5), dhclient.conf(5).

AUTHOR
       omshell	was  written by Ted Lemon of Nominum, Inc.  Information about Nominum and support
       contracts for DHCP and BIND can be found at http://www.nominum.com. This preliminary docu-
       mentation was written by Wendy Verschoor of Nominum, Inc., while she was testing omshell.

										       omshell(1)


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