DHCLIENT.CONF(5)

NAME
dhclient.conf - DHCP client configuration file

DESCRIPTION
dhclient.conf is the configuration file for dhclient(8). It is a free-form ASCII text file made up of declarations, extra tabs and newlines for formatting purposes and comments. Keywords in the file are case-insensitive. Comments begin with the ‘#’ character and extend to the end of the current line.

PROTOCOL TIMING DECLARATIONS

backoff-cutoff seconds;
    Sets the maximum number of seconds to wait before retransmitting a packet. The default is 10 seconds.

initial-interval seconds;
    Sets the number of seconds between the first packet transmission and the first retransmission of the packet. The default is 1 second.

link-timeout seconds;
    Sets the number of seconds to wait for a lease before going into the background as a daemon. The default is 10 seconds.

reboot seconds;
    Sets the number of seconds to wait before giving up on reacquiring the previous lease, and how long to attempt unicast renewal requests before falling back to broadcast renewal requests. The default is 1 second.

retry seconds;
    Sets the number of seconds to wait before starting a new attempt to obtain a lease. The default is 1 second.

select-timeout seconds;
    Sets the number of seconds to wait for additional leases after the first lease arrives. After select-timeout seconds the best lease received will be selected. The default is 0 seconds, i.e. immediately use the first acceptable lease received.

timeout seconds;
    Sets the number of seconds to wait for a lease. If no lease is received, the first valid lease in dhclient.leases(5) will be used. The default is 30 seconds.

DHCP OPTION DECLARATIONS

append option option-value;
    Append option-value to the value of option in the lease. Each append for option overrides any previous append, default, ignore, prepend or supersede for option.

    If the option's data cannot be appended to, i.e. it has a fixed size, then append will be treated as default.

default option option-value;
    If no value for option is present in the lease, use option-value. Each default for option overrides any previous append, default, ignore, prepend or supersede for option.

ignore [option, ...];
    Discard values provided for the listed options. ignore statements are cumulative, except that an empty list will remove all previously specified options. Each ignore for option overrides any previous append, default, prepend or supersede for option.

prepend option option-value;
    Prepend option-value to the value of option in the lease. Each prepend for option overrides any previous append, default, ignore, prepend or supersede for option.

    If the option's data cannot be prepended to, i.e. it has a fixed size, then prepend will be treated as supersede.

request [option, ...];
    Ask that any lease contain values for the listed options. request statements are cumulative, except that an empty list will remove all previously specified options. The default is to request the options bootfile-name, broadcast-address, classless-static-routes, host-name, domain-name, domain-name-servers, domain-search, routers, subnet-mask, tftp-server-name and time-offset.

require [option, ...];
    Discard leases that do not contain the listed options. require statements are cumulative, except that an empty list will remove all previously specified options. The default is to require the option subnet-mask.

send option option-value;
    Include option-value in requests for a lease. To include multiple options in requests, send can be used multiple times.

supersede option option-value;
    Use option-value for the given option regardless of the value in the lease. Each supersede for option overrides any previous append, default, ignore, prepend or supersede for option.

uselease [option, ...];
    Use the unmodified values provided in the lease for any specified option. uselease statements are cumulative. If no option is specified, all lease option values will be used unmodified. uselease for option overrides any previous append, default, ignore, prepend or supersede for option.

OTHER DECLARATIONS

filename path;
    Use path instead of the file field of the DHCP offer when binding a lease.

fixed-address ip-address;
    Use ip-address instead of the yiaddr field of the DHCP offer when binding a lease.

interface "name" { declaration; ...; }
    Apply any declaration only to the named interface.

reject ip-address;
    Discard leases from the specified address. If more than one reject is present, all leases from any of the addresses will be discarded.

next-server ip-address;
    Use ip-address instead of the siaddr field of the DHCP offer when binding a lease.

server-name host;
    Use host instead of the sname field of the DHCP offer when binding a lease.

FILES
/etc/dhclient.conf
/etc/examples/dhclient.conf

SEE ALSO
dhclient.leases(5), dhcp-options(5), dhcpd.conf(5), dhclient(8), dhcpd(8)