dhclient.conf(5) File Formats Manual dhclient.conf(5) (NAME) dhclient.conf - DHCP (DESCRIPTION) dhclient.conf dhclient DHCP (ISC) . dhclient.conf (ASCII) . dhclient . . . () ( ) . # . dhclient.conf : . DHCP . (PROTOCOL TIMING) . - . DHCPv4 . DHCPv6 . timeout timeout time; timeout . . . (retry) . retry retry time; retry DHCP DHCP . . select-timeout select-timeout time; ( ) DHCP . (offer) . ( ). select-timeout . select-timeout . select- timeout - . reboot reboot time; . INIT-REBOOT . . reboot . reboot . backoff-cutoff backoff-cutoff time; . backoff-cutoff / / time . . initial-interval initial-interval time; initial-interval . . backoff-cutoff . . initial-delay initial-delay time; initial-delay . .. RFC2131 . ISC DHCP . . initial-delay . DHCPv6 (DHCPv6 LEASE SELECTION) DHCPv6 ADVERTISE . . . (required) . -R (IA-NA IA-TA IA-PD) . (preference) . . : bindings * X + addresses * Y + options X = 10000 Y = 100 . RFC 7550 . X = 50 Y = 100 . includes/site.h USE_ORIGINAL_CLIENT_LEASE_WEIGHTS . (LEASE REQUIREMENTS AND REQUESTS) DHCP . . DHCP DHCP . DHCP (DHCP Options) . DHCP dhcp-options(5) . request [ also ] request [ [ option-space . ] option ] [, ... ]; request . request - . DHCPv4 subnet-mask broadcast-address time- offset routers domain-name domain-name-servers host-name DHCPv6 dhcp6 name-servers domain-search . 'request' . . request : request; . 'also request' : also request domain-search, dhcp6.sip-servers-addresses; require [ also ] require [ [ option-space . ] option ] [, ... ]; require . . require . require name-servers; interface eth0 { also require domain-search; } send send [ option declaration ] ; send . dhcp-options(5) . DHCP dhcp-lease-time ( ) . . (DYNAMIC DNS) DNS . . DNS . DHCPv4 DHCPv6 . . (key) (zone) DHCP ( dhcpd.conf(5) ). fqdn : send fqdn.fqdn "grosse.example.com."; send fqdn.encoded on; send fqdn.server-update off; also request fqdn, dhcp6.fqdn; fqdn.fqdn (FQDN) . zone . fqdn.encoded DHCP on off . do-forward-updates do-forward-updates [ flag ] ; DNS DHCP ( dhclient-script(8)) DHCP ( SIG(0) DHCP ) do-forward-updates . DHCP flag true DHCP false . DHCP DNS . (OPTION MODIFIERS) . . . default default [ option declaration ] ; default . supersede supersede [ option declaration ] ; supersede . prepend prepend [ option declaration ] ; ( ) prepend . prepend . - . append append [ option declaration ] ; ( ) append . append . - . (LEASE DECLARATIONS) lease lease { lease-declaration [ ... lease-declaration ] } DHCP ( (PROTOCOL TIMING)) . . (fixed) DHCP BOOTP . lease . : lease dhclient.leases DHCP . dhclient.leases . . lease lease . : bootp; bootp DHCP BOOTP . . . interface "string"; interface . . . dhclient.conf . fixed-address ip-address; fixed-address IP . lease . IP ( 12.34.56.78) . filename "string"; filename . . server-name "string"; server-name . . option option-declaration; option dhclient.conf . script "script-name"; script DHCP . DHCP . ( ) . dhclient-script(8) . vendor option space "name"; vendor option space vendor- encapsulate-options . dhcp-vendor-identifier . dhcp-options(5) . medium "media setup"; medium . (media setup) DHCP . ifconfig . DHCP ( media) . . renew date; rebind date; expire date; renew DHCP . rebind DHCP DHCP . expire DHCP . DHCP - DHCP . . db-time-format default local . default date : // :: (weekday) - . . . . . . db-time-format local date : epoch ; # :: seconds-since-epoch ( " " ). # . (epoch time) . . date never . (ALIAS DECLARATIONS) alias { declarations ... } DHCP TCP/IP DHCP IP (IP alias) IP . DHCP dhcp alias IP . alias lease subnet- mask . alias interface fixed-address IP subnet-mask . medium alias . (OTHER DECLARATIONS) db-time-format [ default | local ] ; db-time-format . default UTC local (seconds-since-epoch) . << (LEASE DECLARATIONS)>> . lease-id-format lease-id-format format; format octal hex . . octal ( ) . hex . lease-id-format default-duid IAID ( DHCPv6) . . octal IAID hex . . reject cidr-ip-address [, ... cidr-ip-address ] ; reject DHCP . DHCP - DHCP . cidr-ip-address ip- address[/prefixlen] ip-address IP prefixlen CIDR . : reject 192.168.0.0/16, 10.0.0.5; << C>> RFC 1918 192.168.0.0/16 10.0.0.5 . interface "name" { declarations ... } . lease alias interface . interface . : ISC dhclient . DHCP . . pseudo "name" "real-name" { declarations ... } DHCP . DHCP DHCP . real-name . . IP . : interface "ep0" { send dhcp-client-identifier "my-client-ep0"; } pseudo "secondary" "ep0" { send dhcp-client-identifier "my-client-ep0-secondary"; script "/etc/dhclient-secondary"; } (up) (down) - . dhclient-script(8) . media "media setup" [ , "media setup", ... ]; media IP . dhcp . - ( ). ( DHCPDISCOVER DHCPOFFER) . dhcp . . . hardware link-type mac-address; hardware MAC DHCP . dhclient MAC . link-type (: 'ethernet') mac-address (octets) . anycast-mac link-type mac-address; anycast-mac MAC dhclient IPv4 . DHCP anycast MAC () DHCP . link-type mac-address hardware . (SAMPLE) NetBSD 1.3 . IP 192.5.5.213 ep0 ( 3com 3C589C) . DHCP . (roam) . timeout 60; retry 60; reboot 10; select-timeout 5; initial-interval 2; reject 192.33.137.209; interface "ep0" { send host-name "andare.example.com"; hardware ethernet 00:a0:24:ab:fb:9c; send dhcp-client-identifier 1:0:a0:24:ab:fb:9c; send dhcp-lease-time 3600; supersede domain-search "example.com", "rc.isc.org", "home.isc.org"; prepend domain-name-servers 127.0.0.1; request subnet-mask, broadcast-address, time-offset, routers, domain-name, domain-name-servers, host-name; require subnet-mask, domain-name-servers; script "CLIENTBINDIR/dhclient-script"; media "media 10baseT/UTP", "media 10base2/BNC"; } alias { interface "ep0"; fixed-address 192.5.5.213; option subnet-mask 255.255.255.255; } dhclient.conf - . dhclient.conf - . (SEE ALSO) dhcp-options(5) dhcp-eval(5) dhclient.leases(5) dhcpd(8) dhcpd.conf(5) RFC2132, RFC2131. (AUTHORS) dhclient(8) Internet Systems Consortium : https://www.isc.org dhclient.conf(5)