[BACK]Return to dhclient.conf.5 CVS log [TXT] [DIR] Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / dhcp / client

Diff for /embedaddon/dhcp/client/dhclient.conf.5 between versions 1.1 and 1.1.1.1

version 1.1, 2012/02/21 22:30:18 version 1.1.1.1, 2012/10/09 09:06:54
Line 1 Line 1
 .\"     $Id$  .\"     $Id$
 .\"  .\"
.\" Copyright (c) 2009-2011 by Internet Systems Consortium, Inc. ("ISC").\" Copyright (c) 2009-2012 by Internet Systems Consortium, Inc. ("ISC")
 .\" Copyright (c) 2004,2007 by Internet Systems Consortium, Inc. ("ISC")  .\" Copyright (c) 2004,2007 by Internet Systems Consortium, Inc. ("ISC")
 .\" Copyright (c) 1996-2003 by Internet Software Consortium  .\" Copyright (c) 1996-2003 by Internet Software Consortium
 .\"  .\"
Line 36  The dhclient.conf file contains configuration informat Line 36  The dhclient.conf file contains configuration informat
 .IR dhclient,  .IR dhclient,
 the Internet Systems Consortium DHCP Client.  the Internet Systems Consortium DHCP Client.
 .PP  .PP
The dhclient.conf file is a free-form ASCII text file.   It is parsed byThe dhclient.conf file is a free-form ASCII text file.  It is parsed by
the recursive-descent parser built into dhclient.   The file may containthe recursive-descent parser built into dhclient.  The file may contain
 extra tabs and newlines for formatting purposes.  Keywords in the file  extra tabs and newlines for formatting purposes.  Keywords in the file
are case-insensitive.   Comments may be placed anywhere within theare case-insensitive.  Comments may be placed anywhere within the
file (except within quotes).   Comments begin with the # character andfile (except within quotes).  Comments begin with the # character and
 end at the end of the line.  end at the end of the line.
 .PP  .PP
 The dhclient.conf file can be used to configure the behaviour of the  The dhclient.conf file can be used to configure the behaviour of the
Line 74  The Line 74  The
 statement determines the amount of time that must pass between the  statement determines the amount of time that must pass between the
 time that the client begins to try to determine its address and the  time that the client begins to try to determine its address and the
 time that it decides that it's not going to be able to contact a  time that it decides that it's not going to be able to contact a
server.   By default, this timeout is sixty seconds.   After theserver.  By default, this timeout is sixty seconds.  After the
 timeout has passed, if there are any static leases defined in the  timeout has passed, if there are any static leases defined in the
 configuration file, or any leases remaining in the lease database that  configuration file, or any leases remaining in the lease database that
 have not yet expired, the client will loop through these leases  have not yet expired, the client will loop through these leases
 attempting to validate them, and if it finds one that appears to be  attempting to validate them, and if it finds one that appears to be
valid, it will use that lease's address.   If there are no validvalid, it will use that lease's address.  If there are no valid
 static leases or unexpired leases in the lease database, the client  static leases or unexpired leases in the lease database, the client
 will restart the protocol after the defined retry interval.  will restart the protocol after the defined retry interval.
 .PP  .PP
Line 93  The Line 93  The
 .I retry  .I retry
 statement determines the time that must pass after the client has  statement determines the time that must pass after the client has
 determined that there is no DHCP server present before it tries again  determined that there is no DHCP server present before it tries again
to contact a DHCP server.   By default, this is five minutes.to contact a DHCP server.  By default, this is five minutes.
 .PP  .PP
 .I The  .I The
 .B select-timeout  .B select-timeout
Line 102  to contact a DHCP server.   By default, this is five m Line 102  to contact a DHCP server.   By default, this is five m
  \fBselect-timeout \fItime\fR\fB;\fR   \fBselect-timeout \fItime\fR\fB;\fR
 .PP  .PP
 It is possible (some might say desirable) for there to be more than  It is possible (some might say desirable) for there to be more than
one DHCP server serving any given network.   In this case, it isone DHCP server serving any given network.  In this case, it is
 possible that a client may be sent more than one offer in response to  possible that a client may be sent more than one offer in response to
its initial lease discovery message.   It may be that one of theseits initial lease discovery message.  It may be that one of these
 offers is preferable to the other (e.g., one offer may have the  offers is preferable to the other (e.g., one offer may have the
 address the client previously used, and the other may not).  address the client previously used, and the other may not).
 .PP  .PP
Line 112  The Line 112  The
 .I select-timeout  .I select-timeout
 is the time after the client sends its first lease discovery request  is the time after the client sends its first lease discovery request
 at which it stops waiting for offers from servers, assuming that it  at which it stops waiting for offers from servers, assuming that it
has received at least one such offer.   If no offers have beenhas received at least one such offer.  If no offers have been
 received by the time the  received by the time the
 .I select-timeout  .I select-timeout
 has expired, the client will accept the first offer that arrives.  has expired, the client will accept the first offer that arrives.
Line 127  will take the first offer it sees. Line 127  will take the first offer it sees.
  \fBreboot \fItime\fR\fB;\fR   \fBreboot \fItime\fR\fB;\fR
 .PP  .PP
 When the client is restarted, it first tries to reacquire the last  When the client is restarted, it first tries to reacquire the last
address it had.   This is called the INIT-REBOOT state.   If it isaddress it had.  This is called the INIT-REBOOT state.  If it is
 still attached to the same network it was attached to when it last  still attached to the same network it was attached to when it last
ran, this is the quickest way to get started.   Theran, this is the quickest way to get started.  The
 .I reboot  .I reboot
 statement sets the time that must elapse after the client first tries  statement sets the time that must elapse after the client first tries
 to reacquire its old address before it gives up and tries to discover  to reacquire its old address before it gives up and tries to discover
a new address.   By default, the reboot timeout is ten seconds.a new address.  By default, the reboot timeout is ten seconds.
 .PP  .PP
 .I The  .I The
 .B backoff-cutoff  .B backoff-cutoff
Line 143  a new address.   By default, the reboot timeout is ten Line 143  a new address.   By default, the reboot timeout is ten
 .PP  .PP
 The client uses an exponential backoff algorithm with some randomness,  The client uses an exponential backoff algorithm with some randomness,
 so that if many clients try to configure themselves at the same time,  so that if many clients try to configure themselves at the same time,
they will not make their requests in lockstep.   Thethey will not make their requests in lockstep.  The
 .I backoff-cutoff  .I backoff-cutoff
 statement determines the maximum amount of time that the client is  statement determines the maximum amount of time that the client is
 allowed to back off, the actual value will be evaluated randomly between  allowed to back off, the actual value will be evaluated randomly between
1/2 to 1 1/2 times the \fItime\fR specified.   It defaults to two minutes.1/2 to 1 1/2 times the \fItime\fR specified.  It defaults to fifteen
 seconds.
 .PP  .PP
 .I The  .I The
 .B initial-interval  .B initial-interval
Line 181  to 5. Line 182  to 5.
 .SH LEASE REQUIREMENTS AND REQUESTS  .SH LEASE REQUIREMENTS AND REQUESTS
 The DHCP protocol allows the client to request that the server send it  The DHCP protocol allows the client to request that the server send it
 specific information, and not send it other information that it is not  specific information, and not send it other information that it is not
prepared to accept.   The protocol also allows the client to rejectprepared to accept.  The protocol also allows the client to reject
 offers from servers if they don't contain information the client  offers from servers if they don't contain information the client
 needs, or if the information provided is not satisfactory.  needs, or if the information provided is not satisfactory.
 .PP  .PP
Line 198  are called \fIDHCP Options\fR.  DHCP Options are defin Line 199  are called \fIDHCP Options\fR.  DHCP Options are defin
 .PP  .PP
 The request statement causes the client to request that any server  The request statement causes the client to request that any server
 responding to the client send the client its values for the specified  responding to the client send the client its values for the specified
options.   Only the option names should be specified in the requestoptions.  Only the option names should be specified in the request
statement - not option parameters.   By default, the DHCPv4 clientstatement - not option parameters.  By default, the DHCPv4 client
 requests the subnet-mask, broadcast-address, time-offset, routers,  requests the subnet-mask, broadcast-address, time-offset, routers,
 domain-name, domain-name-servers and host-name options while the DHCPv6  domain-name, domain-name-servers and host-name options while the DHCPv6
 client requests the dhcp6 name-servers and domain-search options.  Note  client requests the dhcp6 name-servers and domain-search options.  Note
Line 207  that if you enter a \'request\' statement, you over-ri Line 208  that if you enter a \'request\' statement, you over-ri
 and these options will not be requested.  and these options will not be requested.
 .PP  .PP
 In some cases, it may be desirable to send no parameter request list  In some cases, it may be desirable to send no parameter request list
at all.   To do this, simply write the request statement but specifyat all.  To do this, simply write the request statement but specify
 no parameters:  no parameters:
 .PP  .PP
 .nf  .nf
Line 229  is best to \'also request\' the additional options: Line 230  is best to \'also request\' the additional options:
  \fB[ also ] require [ [ \fIoption-space\fR . ] \fIoption\fR ] [\fB,\fI ... ]\fB;\fR   \fB[ also ] require [ [ \fIoption-space\fR . ] \fIoption\fR ] [\fB,\fI ... ]\fB;\fR
 .PP  .PP
 The require statement lists options that must be sent in order for an  The require statement lists options that must be sent in order for an
offer to be accepted.   Offers that do not contain all the listedoffer to be accepted.  Offers that do not contain all the listed
 options will be ignored.  There is no default require list.  options will be ignored.  There is no default require list.
 .PP  .PP
 .nf  .nf
Line 257  that will allow it to differentiate between this clien Line 258  that will allow it to differentiate between this clien
 clients or kinds of clients.  clients or kinds of clients.
 .SH DYNAMIC DNS  .SH DYNAMIC DNS
 The client now has some very limited support for doing DNS updates  The client now has some very limited support for doing DNS updates
when a lease is acquired.   This is prototypical, and probably doesn'twhen a lease is acquired.  This is prototypical, and probably doesn't
do what you want.   It also only works if you happen to have controldo what you want.  It also only works if you happen to have control
 over your DNS server, which isn't very likely.  over your DNS server, which isn't very likely.
 .PP  .PP
 Note that everything in this section is true whether you are using DHCPv4  Note that everything in this section is true whether you are using DHCPv4
 or DHCPv6.  The exact same syntax is used for both.  or DHCPv6.  The exact same syntax is used for both.
 .PP  .PP
 To make it work, you have to declare a key and zone as in the DHCP  To make it work, you have to declare a key and zone as in the DHCP
server (see \fBdhcpd.conf\fR(5) for details).   You also need toserver (see \fBdhcpd.conf\fR(5) for details).  You also need to
 configure the fqdn option on the client, as follows:  configure the fqdn option on the client, as follows:
 .PP  .PP
 .nf  .nf
Line 276  configure the fqdn option on the client, as follows: Line 277  configure the fqdn option on the client, as follows:
 .fi  .fi
 .PP  .PP
 The \fIfqdn.fqdn\fR option \fBMUST\fR be a fully-qualified domain  The \fIfqdn.fqdn\fR option \fBMUST\fR be a fully-qualified domain
name.   You \fBMUST\fR define a zone statement for the zone to bename.  You \fBMUST\fR define a zone statement for the zone to be
updated.   The \fIfqdn.encoded\fR option may need to be set toupdated.  The \fIfqdn.encoded\fR option may need to be set to
 \fIon\fR or \fIoff\fR, depending on the DHCP server you are using.  \fIon\fR or \fIoff\fR, depending on the DHCP server you are using.
 .PP  .PP
 .I The  .I The
Line 291  script (see \fBdhclient-script(8)\fR) rather than havi Line 292  script (see \fBdhclient-script(8)\fR) rather than havi
 DHCP client do the update directly (for example, if you want to  DHCP client do the update directly (for example, if you want to
 use SIG(0) authentication, which is not supported directly by the  use SIG(0) authentication, which is not supported directly by the
 DHCP client, you can instruct the client not to do the update using  DHCP client, you can instruct the client not to do the update using
the \fBdo-forward-updates\fR statement.   \fIFlag\fR should be \fBtrue\fRthe \fBdo-forward-updates\fR statement.  \fIFlag\fR should be \fBtrue\fR
 if you want the DHCP client to do the update, and \fBfalse\fR if  if you want the DHCP client to do the update, and \fBfalse\fR if
you don't want the DHCP client to do the update.   By default, the DHCPyou don't want the DHCP client to do the update.  By default, the DHCP
 client will do the DNS update.  client will do the DNS update.
 .SH OPTION MODIFIERS  .SH OPTION MODIFIERS
 In some cases, a client may receive option data from the server which  In some cases, a client may receive option data from the server which
 is not really appropriate for that client, or may not receive  is not really appropriate for that client, or may not receive
 information that it needs, and for which a useful default value  information that it needs, and for which a useful default value
exists.   It may also receive information which is useful, but whichexists.  It may also receive information which is useful, but which
needs to be supplemented with local information.   To handle theseneeds to be supplemented with local information.  To handle these
 needs, several option modifiers are available.  needs, several option modifiers are available.
 .PP  .PP
 .I The  .I The
Line 337  If for some set of options the client should use a val Line 338  If for some set of options the client should use a val
 supply, and then use the values supplied by  supply, and then use the values supplied by
 the server, if any, these values can be defined in the  the server, if any, these values can be defined in the
 .B prepend  .B prepend
statement.   Thestatement.  The
 .B prepend  .B prepend
 statement can only be used for options which  statement can only be used for options which
allow more than one value to be given.   This restriction is notallow more than one value to be given.  This restriction is not
 enforced - if you ignore it, the behaviour will be unpredictable.  enforced - if you ignore it, the behaviour will be unpredictable.
 .PP  .PP
 .I The  .I The
Line 353  If for some set of options the client should first use Line 354  If for some set of options the client should first use
 supplied by the server, if any, and then use values you supply, these  supplied by the server, if any, and then use values you supply, these
 values can be defined in the  values can be defined in the
 .B append  .B append
statement.   Thestatement.  The
 .B append  .B append
 statement can only be used for options which  statement can only be used for options which
allow more than one value to be given.   This restriction is notallow more than one value to be given.  This restriction is not
 enforced - if you ignore it, the behaviour will be unpredictable.  enforced - if you ignore it, the behaviour will be unpredictable.
 .SH LEASE DECLARATIONS  .SH LEASE DECLARATIONS
 .PP  .PP
Line 368  enforced - if you ignore it, the behaviour will be unp Line 369  enforced - if you ignore it, the behaviour will be unp
 .PP  .PP
 The DHCP client may decide after some period of time (see \fBPROTOCOL  The DHCP client may decide after some period of time (see \fBPROTOCOL
 TIMING\fR) that it is not going to succeed in contacting a  TIMING\fR) that it is not going to succeed in contacting a
server.   At that time, it consults its own database of old leases andserver.  At that time, it consults its own database of old leases and
 tests each one that has not yet timed out by pinging the listed router  tests each one that has not yet timed out by pinging the listed router
for that lease to see if that lease could work.   It is possible tofor that lease to see if that lease could work.  It is possible to
 define one or more \fIfixed\fR leases in the client configuration file  define one or more \fIfixed\fR leases in the client configuration file
 for networks where there is no DHCP or BOOTP service, so that the  for networks where there is no DHCP or BOOTP service, so that the
client can still automatically configure its address.   This is doneclient can still automatically configure its address.  This is done
 with the  with the
 .B lease  .B lease
 statement.  statement.
Line 381  statement. Line 382  statement.
 NOTE: the lease statement is also used in the dhclient.leases file in  NOTE: the lease statement is also used in the dhclient.leases file in
 order to record leases that have been received from DHCP servers.  order to record leases that have been received from DHCP servers.
 Some of the syntax for leases as described below is only needed in the  Some of the syntax for leases as described below is only needed in the
dhclient.leases file.   Such syntax is documented here fordhclient.leases file.  Such syntax is documented here for
 completeness.  completeness.
 .PP  .PP
 A lease statement consists of the lease keyword, followed by a left  A lease statement consists of the lease keyword, followed by a left
 curly brace, followed by one or more lease declaration statements,  curly brace, followed by one or more lease declaration statements,
followed by a right curly brace.   The following lease declarationsfollowed by a right curly brace.  The following lease declarations
 are possible:  are possible:
 .PP  .PP
  \fBbootp;\fR   \fBbootp;\fR
Line 394  are possible: Line 395  are possible:
 The  The
 .B bootp  .B bootp
 statement is used to indicate that the lease was acquired using the  statement is used to indicate that the lease was acquired using the
BOOTP protocol rather than the DHCP protocol.   It is never necessaryBOOTP protocol rather than the DHCP protocol.  It is never necessary
to specify this in the client configuration file.   The client usesto specify this in the client configuration file.  The client uses
 this syntax in its lease database file.  this syntax in its lease database file.
 .PP  .PP
  \fBinterface\fR \fB"\fR\fIstring\fR\fB";\fR   \fBinterface\fR \fB"\fR\fIstring\fR\fB";\fR
Line 403  this syntax in its lease database file. Line 404  this syntax in its lease database file.
 The  The
 .B interface  .B interface
 lease statement is used to indicate the interface on which the lease  lease statement is used to indicate the interface on which the lease
is valid.   If set, this lease will only be tried on a particularis valid.  If set, this lease will only be tried on a particular
interface.   When the client receives a lease from a server, it alwaysinterface.  When the client receives a lease from a server, it always
 records the interface number on which it received that lease.  records the interface number on which it received that lease.
 If predefined leases are specified in the dhclient.conf file, the  If predefined leases are specified in the dhclient.conf file, the
 interface should also be specified, although this is not required.  interface should also be specified, although this is not required.
Line 413  interface should also be specified, although this is n Line 414  interface should also be specified, although this is n
 .PP  .PP
 The  The
 .B fixed-address  .B fixed-address
statement is used to set the ip address of a particular lease.   Thisstatement is used to set the ip address of a particular lease.  This
is required for all lease statements.   The IP address must beis required for all lease statements.  The IP address must be
 specified as a dotted quad (e.g., 12.34.56.78).  specified as a dotted quad (e.g., 12.34.56.78).
 .PP  .PP
  \fBfilename "\fR\fIstring\fR\fB";\fR   \fBfilename "\fR\fIstring\fR\fB";\fR
 .PP  .PP
 The  The
 .B filename  .B filename
statement specifies the name of the boot filename to use.   This isstatement specifies the name of the boot filename to use.  This is
 not used by the standard client configuration script, but is included  not used by the standard client configuration script, but is included
 for completeness.  for completeness.
 .PP  .PP
Line 429  for completeness. Line 430  for completeness.
 .PP  .PP
 The  The
 .B server-name  .B server-name
statement specifies the name of the boot server name to use.   This isstatement specifies the name of the boot server name to use.  This is
 also not used by the standard client configuration script.  also not used by the standard client configuration script.
 .PP  .PP
  \fBoption\fR \fIoption-declaration\fR\fB;\fR   \fBoption\fR \fIoption-declaration\fR\fB;\fR
Line 449  statement is used to specify the pathname of the dhcp  Line 450  statement is used to specify the pathname of the dhcp 
 configuration script.  This script is used by the dhcp client to set  configuration script.  This script is used by the dhcp client to set
 each interface's initial configuration prior to requesting an address,  each interface's initial configuration prior to requesting an address,
 to test the address once it has been offered, and to set the  to test the address once it has been offered, and to set the
interface's final configuration once a lease has been acquired.   Ifinterface's final configuration once a lease has been acquired.  If
 no lease is acquired, the script is used to test predefined leases, if  no lease is acquired, the script is used to test predefined leases, if
any, and also called once if no valid lease can be identified.   Forany, and also called once if no valid lease can be identified.  For
 more information, see  more information, see
 .B dhclient-script(8).  .B dhclient-script(8).
 .PP  .PP
Line 462  The Line 463  The
 statement is used to specify which option space should be used for  statement is used to specify which option space should be used for
 decoding the vendor-encapsulate-options option if one is received.  decoding the vendor-encapsulate-options option if one is received.
 The \fIdhcp-vendor-identifier\fR can be used to request a specific  The \fIdhcp-vendor-identifier\fR can be used to request a specific
class of vendor options from the server.   Seeclass of vendor options from the server.  See
 .B dhcp-options(5)  .B dhcp-options(5)
 for details.  for details.
 .PP  .PP
Line 493  interface requires media type configuration. Line 494  interface requires media type configuration.
 .PP  .PP
 The \fBrenew\fR statement defines the time at which the dhcp client  The \fBrenew\fR statement defines the time at which the dhcp client
 should begin trying to contact its server to renew a lease that it is  should begin trying to contact its server to renew a lease that it is
using.   The \fBrebind\fR statement defines the time at which the dhcpusing.  The \fBrebind\fR statement defines the time at which the dhcp
 client should begin to try to contact \fIany\fR dhcp server in order  client should begin to try to contact \fIany\fR dhcp server in order
to renew its lease.   The \fBexpire\fR statement defines the time atto renew its lease.  The \fBexpire\fR statement defines the time at
 which the dhcp client must stop using a lease if it has not been able  which the dhcp client must stop using a lease if it has not been able
 to contact a server in order to renew it.  to contact a server in order to renew it.
 .PP  .PP
Line 547  instead of an actual date. Line 548  instead of an actual date.
 Some DHCP clients running TCP/IP roaming protocols may require that in  Some DHCP clients running TCP/IP roaming protocols may require that in
 addition to the lease they may acquire via DHCP, their interface also  addition to the lease they may acquire via DHCP, their interface also
 be configured with a predefined IP alias so that they can have a  be configured with a predefined IP alias so that they can have a
permanent IP address even while roaming.   The Internet Systemspermanent IP address even while roaming.  The Internet Systems
 Consortium DHCP client doesn't support roaming with fixed addresses  Consortium DHCP client doesn't support roaming with fixed addresses
 directly, but in order to facilitate such experimentation, the dhcp  directly, but in order to facilitate such experimentation, the dhcp
 client can be set up to configure an IP alias using the  client can be set up to configure an IP alias using the
Line 559  options other than the subnet-mask option are ignored  Line 560  options other than the subnet-mask option are ignored 
 client configuration script, and expiry times are ignored.  A typical  client configuration script, and expiry times are ignored.  A typical
 alias declaration includes an interface declaration, a fixed-address  alias declaration includes an interface declaration, a fixed-address
 declaration for the IP alias address, and a subnet-mask option  declaration for the IP alias address, and a subnet-mask option
declaration.   A medium statement should never be included in an aliasdeclaration.  A medium statement should never be included in an alias
 declaration.  declaration.
 .SH OTHER DECLARATIONS  .SH OTHER DECLARATIONS
  \fBdb-time-format\fR [ \fIdefault\fR | \fIlocal\fR ] \fB;\fR   \fBdb-time-format\fR [ \fIdefault\fR | \fIlocal\fR ] \fB;\fR
Line 588  the subnet, counting the number of significant bits in Line 589  the subnet, counting the number of significant bits in
 from the leftmost end.  Example configuration syntax:  from the leftmost end.  Example configuration syntax:
 .PP  .PP
 .I \fIreject\fR 192.168.0.0\fB/\fR16\fB,\fR 10.0.0.5\fB;\fR  .I \fIreject\fR 192.168.0.0\fB/\fR16\fB,\fR 10.0.0.5\fB;\fR
 .RE  
 .PP  .PP
 The above example would cause offers from any server identifier in the  The above example would cause offers from any server identifier in the
 entire RFC 1918 "Class C" network 192.168.0.0/16, or the specific  entire RFC 1918 "Class C" network 192.168.0.0/16, or the specific
Line 597  single address 10.0.0.5, to be rejected. Line 597  single address 10.0.0.5, to be rejected.
  \fBinterface "\fIname\fB" { \fIdeclarations ... \fB }   \fBinterface "\fIname\fB" { \fIdeclarations ... \fB }
 .PP  .PP
 A client with more than one network interface may require different  A client with more than one network interface may require different
behaviour depending on which interface is being configured.   Allbehaviour depending on which interface is being configured.  All
 timing parameters and declarations other than lease and alias  timing parameters and declarations other than lease and alias
 declarations can be enclosed in an interface declaration, and those  declarations can be enclosed in an interface declaration, and those
 parameters will then be used only for the interface that matches the  parameters will then be used only for the interface that matches the
specified name.   Interfaces for which there is no interfacespecified name.  Interfaces for which there is no interface
 declaration will use the parameters declared outside of any interface  declaration will use the parameters declared outside of any interface
 declaration, or the default settings.  declaration, or the default settings.
 .PP  .PP
Line 622  Each interface that the DHCP client is supporting norm Line 622  Each interface that the DHCP client is supporting norm
 client state machine running on it to acquire and maintain its lease.  client state machine running on it to acquire and maintain its lease.
 A pseudo-interface is just another state machine running on the  A pseudo-interface is just another state machine running on the
 interface named \fIreal-name\fR, with its own lease and its own  interface named \fIreal-name\fR, with its own lease and its own
state.   If you use this feature, you must provide a client identifierstate.  If you use this feature, you must provide a client identifier
 for both the pseudo-interface and the actual interface, and the two  for both the pseudo-interface and the actual interface, and the two
identifiers must be different.   You must also provide a separateidentifiers must be different.  You must also provide a separate
 client script for the pseudo-interface to do what you want with the IP  client script for the pseudo-interface to do what you want with the IP
address.   For example:address.  For example:
 .PP  .PP
 .nf  .nf
         interface "ep0" {          interface "ep0" {
Line 641  address.   For example: Line 641  address.   For example:
 The client script for the pseudo-interface should not configure the  The client script for the pseudo-interface should not configure the
 interface up or down - essentially, all it needs to handle are the  interface up or down - essentially, all it needs to handle are the
 states where a lease has been acquired or renewed, and the states  states where a lease has been acquired or renewed, and the states
where a lease has expired.   See \fBdhclient-script(8)\fR for morewhere a lease has expired.  See \fBdhclient-script(8)\fR for more
 information.  information.
 .PP  .PP
  \fBmedia "\fImedia setup\fB"\fI [ \fB, "\fImedia setup\fB", \fI... ]\fB;\fR   \fBmedia "\fImedia setup\fB"\fI [ \fB, "\fImedia setup\fB", \fI... ]\fB;\fR
Line 649  information. Line 649  information.
 The  The
 .B media  .B media
 statement defines one or more media configuration parameters which may  statement defines one or more media configuration parameters which may
be tried while attempting to acquire an IP address.   The dhcp clientbe tried while attempting to acquire an IP address.  The dhcp client
 will cycle through each media setup string on the list, configuring  will cycle through each media setup string on the list, configuring
 the interface using that setup and attempting to boot, and then trying  the interface using that setup and attempting to boot, and then trying
the next one.   This can be used for network interfaces which aren'tthe next one.  This can be used for network interfaces which aren't
 capable of sensing the media type unaided - whichever media type  capable of sensing the media type unaided - whichever media type
 succeeds in getting a request to the server and hearing the reply is  succeeds in getting a request to the server and hearing the reply is
 probably right (no guarantees).  probably right (no guarantees).
 .PP  .PP
 The media setup is only used for the initial phase of address  The media setup is only used for the initial phase of address
acquisition (the DHCPDISCOVER and DHCPOFFER packets).   Once anacquisition (the DHCPDISCOVER and DHCPOFFER packets).  Once an
 address has been acquired, the dhcp client will record it in its lease  address has been acquired, the dhcp client will record it in its lease
 database and will record the media type used to acquire the address.  database and will record the media type used to acquire the address.
 Whenever the client tries to renew the lease, it will use that same  Whenever the client tries to renew the lease, it will use that same
media type.   The lease must expire before the client will go back tomedia type.  The lease must expire before the client will go back to
 cycling through media types.  cycling through media types.
 .SH SAMPLE  .SH SAMPLE
 The following configuration file is used on a laptop running NetBSD  The following configuration file is used on a laptop running NetBSD
1.3.   The laptop has an IP alias of 192.5.5.213, and has one1.3.  The laptop has an IP alias of 192.5.5.213, and has one
interface, ep0 (a 3com 3C589C).   Booting intervals have beeninterface, ep0 (a 3com 3C589C).  Booting intervals have been
 shortened somewhat from the default, because the client is known to  shortened somewhat from the default, because the client is known to
spend most of its time on networks with little DHCP activity.   Thespend most of its time on networks with little DHCP activity.  The
 laptop does roam to multiple networks.  laptop does roam to multiple networks.
   
 .nf  .nf
Line 701  alias { Line 701  alias {
 }  }
 .fi  .fi
 This is a very complicated dhclient.conf file - in general, yours  This is a very complicated dhclient.conf file - in general, yours
should be much simpler.   In many cases, it's sufficient to justshould be much simpler.  In many cases, it's sufficient to just
 create an empty dhclient.conf file - the defaults are usually fine.  create an empty dhclient.conf file - the defaults are usually fine.
 .SH SEE ALSO  .SH SEE ALSO
 dhcp-options(5), dhcp-eval(5), dhclient.leases(5), dhcpd(8), dhcpd.conf(5),  dhcp-options(5), dhcp-eval(5), dhclient.leases(5), dhcpd(8), dhcpd.conf(5),
Line 709  RFC2132, RFC2131. Line 709  RFC2132, RFC2131.
 .SH AUTHOR  .SH AUTHOR
 .B dhclient(8)  .B dhclient(8)
 was written by Ted Lemon  was written by Ted Lemon
under a contract with Vixie Labs.   Fundingunder a contract with Vixie Labs.  Funding
 for this project was provided by Internet Systems Consortium.  for this project was provided by Internet Systems Consortium.
 Information about Internet Systems Consortium can be found at  Information about Internet Systems Consortium can be found at
 .B https://www.isc.org.  .B https://www.isc.org.
Removed from v.1.1  
changed lines
  Added in v.1.1.1.1

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>