.\" Copyright (c) 2006-2012 Roy Marples .\" All rights reserved .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .Dd March 19, 2012 .Dt DHCPCD.CONF 5 SMM .Os .Sh NAME .Nm dhcpcd.conf .Nd dhcpcd configuration file .Sh DESCRIPTION Although .Nm dhcpcd can do everything from the command line, there are cases where it's just easier to do it once in a configuration file. Most of the options found in .Xr dhcpcd 8 can be used here. The first word on the line is the option and the rest of the line is the value. Leading and trailing whitespace for the option and value are trimmed. You can escape characters in the value using the \\ character. .Pp Blank lines and lines starting with # are ignored. .Pp Here's a list of available options: .Bl -tag -width indent .It Ic allowinterfaces Ar pattern When discovering interfaces, the interface name must match .Ar pattern which is a space or comma separated list of patterns passed to .Xr fnmatch 3 . If the same interface is matched in .Ic denyinterfaces then it is still denied. .It Ic denyinterfaces Ar pattern When discovering interfaces, the interface name must not match .Ar pattern which is a space or comma separated list of patterns passed to .Xr fnmatch 3 . .It Ic arping Ar address Op address .Nm dhcpcd will arping each address in order before attempting DHCP. If an address is found, we will select the replying hardware address as the profile, otherwise the ip address. Example: .Pp .D1 interface bge0 .D1 arping 192.168.0.1 .Pp .D1 profile 192.168.0.1 .D1 static ip_address=192.168.0.10/24 .It Ic background Background immediately. This is useful for startup scripts which don't disable link messages for carrier status. .It Ic blacklist Ar address Ns Op /cidr Ignores all packets from .Ar address Ns Op /cidr . .It Ic whitelist Ar address Ns Op /cidr Only accept packets from .Ar address Ns Op /cidr . .Ic blacklist is ignored if .Ic whitelist is set. .It Ic broadcast Instructs the DHCP server to broadcast replies back to the client. Normally this is only set for non Ethernet interfaces, such as FireWire and InfiniBand. In most cases, .Nm dhcpcd will set this automatically. .It Ic env Ar value Push .Ar value to the environment for use in .Xr dhcpcd-run-hooks 8 . For example, you can force the hostname hook to always set the hostname with .Ic env .Va force_hostname=YES . .It Ic clientid Ar string Send the .Ar clientid . If the string is of the format 01:02:03 then it is encoded as hex. For interfaces whose hardware address is longer than 8 bytes, or if the .Ar clientid is an empty string then .Nm dhcpcd sends a default .Ar clientid of the hardware family and the hardware address. .It Ic duid Generate an .Rs .%T "RFC 4361" .Re compliant clientid. This requires persistent storage and not all DHCP servers work with it so it's not enabled by default. The duid generated will be held in .Pa @SYSCONFDIR@/dhcpcd.duid and should not be copied to other hosts. .It Ic fallback Ar profile Fallback to using this profile if DHCP fails. This allows you to configure a static profile instead of using ZeroConf. .It Ic hostname Ar name Sends .Ar hostname to the DHCP server so it can be registered in DNS. If .Ar hostname is an empty string then the current system hostname is sent. If .Ar hostname is a FQDN (ie, contains a .) then it will be encoded as such. .It Ic fqdn Op none | ptr | both none disables FQDN encoding, ptr just asks the DHCP server to update the PTR record of the host in DNS whereas both also updates the A record. .Nm dhcpcd itself never does any DNS updates. .Nm dhcpcd encodes the FQDN hostname as specified in .Li RFC1035 . .It Ic interface Ar interface Subsequent options are only parsed for this .Ar interface . .It Ic ipv6ra_fork By default, when .Nm dhcpcd receives an IPv6 RA, .Nm dhcpcd will only fork to the background if the RA contains at least one unexpired RDNSS option. Set this option so to make .Nm dhcpcd always fork on an RA. .It Ic leasetime Ar seconds Request a leasetime of .Ar seconds . .It Ic metric Ar metric Metrics are used to prefer an interface over another one, lowest wins. .Nm dhcpcd will supply a default metric of 200 + .Xr if_nametoindex 3 . An extra 100 will be added for wireless interfaces. .It Ic noarp Don't send any ARP requests. This also disables IPv4LL. .It Ic nogateway Don't install any default routes. .It Ic nohook Ar script Don't run this hook script. Matches full name, or prefixed with 2 numbers optionally ending with .Pa .sh . .Pp So to stop .Nm dhcpcd from touching your DNS or MTU settings you would do:- .D1 nohook resolv.conf, mtu .It Ic noipv4ll Don't attempt to obtain an IPv4LL address if we failed to get one via DHCP. See .Rs .%T "RFC 3927" .Re .It Ic noipv6rs Disable solicition of IPv6 Router Advertisements. .It Ic nolink Don't receive link messages about carrier status. You should only set this for buggy interface drivers. .It Ic option Ar option Requests the .Ar option from the server. It can be a variable to be used in .Xr dhcpcd-run-hooks 8 or the numerical value. You can specify more options separated by commas, spaces or more option lines. .It Ic nooption Ar option Remove the option from the DHCP message. This should only be used when a DHCP server sends a non requested option that should not be processed. .It Ic destination Ar option If .Nm detects an address added to a point to point interface (PPP, TUN, etc) then it will set the listed DHCP options to the destination address of the interface. .It Ic profile Ar name Subsequent options are only parsed for this profile .Ar name . .It Ic quiet Suppress any dhcpcd output to the console, except for errors. .It Ic reboot Ar seconds Allow .Ar reboot seconds before moving to the discover phase if we have an old lease to use. The default is 5 seconds. A setting if 0 seconds causes .Nm dhcpcd to skip the reboot phase and go straight into discover. .It Ic release .Nm dhcpcd will release the lease prior to stopping the interface. .It Ic require Ar option Requires the .Ar option to be present in all DHCP messages, otherwise the message is ignored. It can be a variable to be used in .Xr dhcpcd-run-hooks 8 or the numerical value. You can specify more options separated by commas, spaces or more require lines. To enforce that .Nm dhcpcd only responds to DHCP servers and not BOOTP servers, you can .Ic require .Ar dhcp_message_type . .It Ic script Ar script Use .Ar script instead of the default .Pa @SCRIPT@ . .It Ic ssid Ar ssid Subsequent options are only parsed for this wireless .Ar ssid . .It Ic static Ar value Configures a static .Ar value . If you set .Ic ip_address then .Nm dhcpcd will not attempt to obtain a lease and just use the value for the address with an infinite lease time. .Pp Here is an example which configures a static address, routes and dns. .D1 interface eth0 .D1 static ip_address=192.168.0.10/24 .D1 static routers=192.168.0.1 .D1 static domain_name_servers=192.168.0.1 .Pp Here is an example for PPP which gives the destination a default route. It uses the special destination keyword to insert the destination address into the value. .D1 interface ppp0 .D1 static ip_address= .D1 destination routers .It Ic timeout Ar seconds The default timeout for waiting for a DHCP response is 30 seconds which may be too long or too short and can be changed here. .It Ic userclass Ar string Tag the DHCP messages with the userclass. You can specify more than one. .It Ic vendor Ar code , Ns Ar value Add an encapsulated vendor option. .Ar code should be between 1 and 254 inclusive. To add a raw vendor string, omit .Ar code but keep the comma. Examples. .Pp Set the vendor option 01 with an IP address. .D1 vendor 01,192.168.0.2 Set the vendor option 02 with a hex code. .D1 vendor 02,01:02:03:04:05 Set the vendor option 03 with an IP address as a string. .D1 vendor 03,\e"192.168.0.2\e" Set un-encapsulated vendor option to hello world. .D1 vendor ,"hello world" .It Ic vendorclassid Ar string Change the default vendorclassid sent from dhcpcd-version. If not set then none is sent. .It Ic waitip Wait for an address to be assigned before forking to the background. .It Ic xidhwaddr Use the last four bytes of the hardware address as the DHCP xid instead of a randomly generated number. .El .Sh SEE ALSO .Xr dhcpcd-run-hooks 8 , .Xr dhcpcd 8 , .Xr if_nametoindex 3 , .Xr fnmatch 3 .Sh AUTHORS .An Roy Marples Aq roy@marples.name .Sh BUGS Please report them to .Lk http://roy.marples.name/projects/dhcpcd