DHCPCD.CONF(5) System Manager's Manual DHCPCD.CONF(5)
dhcpcd.conf -- dhcpcd configuration file
Although 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 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.
Blank lines and lines starting with # are ignored.
Here's a list of available options:
When discovering interfaces, the interface name must match
pattern which is a space or comma separated list of patterns
passed to fnmatch(3). If the same interface is matched in
denyinterfaces then it is still denied.
When discovering interfaces, the interface name must not match
pattern which is a space or comma separated list of patterns
passed to fnmatch(3).
arping address [address]
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:
Background immediately. This is useful for startup scripts which
don't disable link messages for carrier status.
Ignores all packets from address[/cidr].
Only accept packets from address[/cidr]. blacklist is ignored if
whitelist is set.
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, dhcpcd will set
Push value to the environment for use in dhcpcd-run-hooks(8).
For example, you can force the hostname hook to always set the
hostname with env force_hostname=YES.
Send the 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 clientid is an empty string then
dhcpcd sends a default clientid of the hardware family and the
duid Generate an RFC 4361. 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
/etc/dhcpcd.duid and should not be copied to other hosts.
Fallback to using this profile if DHCP fails. This allows you to
configure a static profile instead of using ZeroConf.
Sends hostname to the DHCP server so it can be registered in DNS.
If hostname is an empty string then the current system hostname
is sent. If hostname is a FQDN (ie, contains a .) then it will
be encoded as such.
fqdn [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. dhcpcd itself never does any DNS updates.
dhcpcd encodes the FQDN hostname as specified in RFC1035.
Subsequent options are only parsed for this interface.
By default, when dhcpcd receives an IPv6 RA, dhcpcd will only
fork to the background if the RA contains at least one unexpired
RDNSS option. Set this option so to make dhcpcd always fork on
Disables kernel IPv6 Router Advertisment processing so dhcpcd can
manage addresses and routes.
Each time dhcpcd receives an IPv6 Router Adveristment, dhcpcd
will manage the default route only. This allows dhcpcd to prefer
an interface for outbound traffic based on metric and/or user
selection rather than the kernel.
Enables IPv6 Router Advertisment solicitation. This is on by
default, but is documented here in the case where it is disabled
globally but needs to be enabled for one interface.
Request a leasetime of seconds.
Metrics are used to prefer an interface over another one, lowest
wins. dhcpcd will supply a default metric of 200 +
if_nametoindex(3). An extra 100 will be added for wireless
noarp Don't send any ARP requests. This also disables IPv4LL.
Don't install any default routes.
Don't run this hook script. Matches full name, or prefixed with
2 numbers optionally ending with .sh.
So to stop dhcpcd from touching your DNS or MTU settings you
nohook resolv.conf, mtu
Don't attempt to obtain an IPv4LL address if we failed to get one
via DHCP. See RFC 3927.
Disable solicition of IPv6 Router Advertisements.
nolink Don't receive link messages about carrier status. You should
only set this for buggy interface drivers.
Requests the option from the server. It can be a variable to be
used in dhcpcd-run-hooks(8) or the numerical value. You can
specify more options separated by commas, spaces or more 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.
If dhcpcd.conf 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.
Subsequent options are only parsed for this profile name.
quiet Suppress any dhcpcd output to the console, except for errors.
Allow 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 dhcpcd to skip the reboot phase and go
straight into discover.
dhcpcd will release the lease prior to stopping the interface.
Requires the option to be present in all DHCP messages, otherwise
the message is ignored. It can be a variable to be used in
dhcpcd-run-hooks(8) or the numerical value. You can specify more
options separated by commas, spaces or more require lines. To
enforce that dhcpcd only responds to DHCP servers and not BOOTP
servers, you can require dhcp_message_type.
Use script instead of the default /libexec/dhcpcd-run-hooks.
Subsequent options are only parsed for this wireless ssid.
Configures a static value. If you set ip_address then dhcpcd
will not attempt to obtain a lease and just use the value for the
address with an infinite lease time.
Here is an example which configures a static address, routes and
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.
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.
Tag the DHCP messages with the userclass. You can specify more
Add an encapsulated vendor option. code should be between 1 and
254 inclusive. To add a raw vendor string, omit code but keep
the comma. Examples.
Set the vendor option 01 with an IP address.
Set the vendor option 02 with a hex code.
Set the vendor option 03 with an IP address as a string.
Set un-encapsulated vendor option to hello world.
vendor ,"hello world"
The default is dhcpcd-<version>:<os>:<machine>:<platform>. For
If not set then none is sent. Some badly configured DHCP servers
reject unknown vendorclassids. To work around it, try and
impersonate Windows by using the MSFT vendorclassid.
waitip Wait for an address to be assigned before forking to the
Use the last four bytes of the hardware address as the DHCP xid
instead of a randomly generated number.
dhcpcd-run-hooks(8), dhcpcd(8), if_nametoindex(3), fnmatch(3)
Roy Marples <royATmarples.name>
Please report them to http://roy.marples.name/projects/dhcpcd
NetBSD 6.1.5 May 21, 2012 NetBSD 6.1.5