dhcpcd.conf man page on aLinux

Man page or keyword search:  
man Server   7435 pages
apropos Keyword Search (all sections)
Output format
aLinux logo
[printable version]

DHCPCD.CONF(5)		    System Manager's Manual		DHCPCD.CONF(5)

NAME
     dhcpcd.conf — dhcpcd configuration file

DESCRIPTION
     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:

     allowinterfaces pattern
	     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.

     denyinterfaces pattern
	     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:

		   interface bge0
		   arping 192.168.0.1

		   profile 192.168.0.1
		   static ip_address=192.168.0.10/24

     background
	     Background immediately.  This is useful for startup scripts which
	     don't disable link messages for carrier status.

     blacklist address[/cidr]
	     Ignores all packets from address[/cidr].

     whitelist address[/cidr]
	     Only accept packets from address[/cidr].  blacklist is ignored if
	     whitelist is set.

     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, dhcpcd will set
	     this automatically.

     env value
	     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.

     clientid string
	     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
	     hardware address.

     duid    Generate an RFC 4361.  compliant clientid.	 This requires persis‐
	     tent 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 profile
	     Fallback to using this profile if DHCP fails.  This allows you to
	     configure a static profile instead of using ZeroConf.

     hostname name
	     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.

     interface interface
	     Subsequent options are only parsed for this interface.

     leasetime seconds
	     Request a leasetime of seconds.

     metric metric
	     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
	     interfaces.

     noarp   Don't send any ARP requests.  This also disables IPv4LL.

     nogateway
	     Don't install any default routes.

     nohook script
	     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
	     would do:-
		   nohook resolv.conf, mtu

     noipv4ll
	     Don't attempt to obtain an IPv4LL address if we failed to get one
	     via DHCP.	See RFC 3927.

     nolink  Don't receive link messages about carrier status.	You should
	     only set this for buggy interface drivers.

     option option
	     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
	     lines.

     nooption 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.

     destination option
	     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.

     profile name
	     Subsequent options are only parsed for this profile name.

     quiet   Suppress any dhcpcd output to the console, except for errors.

     reboot seconds
	     Allow reboot seconds before moving to the discover phase if we
	     have an old lease to use.	The default is 10 seconds.  A setting
	     if 0 seconds causes dhcpcd to skip the reboot phase and go
	     straight into discover.

     release
	     dhcpcd will release the lease prior to stopping the interface.

     require option
	     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.

     script script
	     Use script instead of the default /lib/dhcpcd-run-hooks.

     ssid ssid
	     Subsequent options are only parsed for this wireless ssid.

     static value
	     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
	     dns.
		   interface eth0
		   static ip_address=192.168.0.10/24
		   static routers=192.168.0.1
		   static domain_name_servers=192.168.0.1

	     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.
		   interface ppp0
		   static ip_address=
		   destination routers

     timeout 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.

     userclass string
	     Tag the DHCP messages with the userclass.	You can specify more
	     than one.

     vendor code,value
	     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.
		   vendor 01,192.168.0.2
	     Set the vendor option 02 with a hex code.
		   vendor 02,01:02:03:04:05
	     Set the vendor option 03 with an IP address as a string.
		   vendor 03,\"192.168.0.2\"
	     Set un-encapsulated vendor option to hello world.
		   vendor ,"hello world"

     vendorclassid string
	     Change the default vendorclassid sent from dhcpcd-version.	 If
	     not set then none is sent.

     waitip  Wait for an address to be assigned before forking to the back‐
	     ground.

     xidhwaddr
	     Use the last four bytes of the hardware address as the DHCP xid
	     instead of a randomly generated number.

SEE ALSO
     dhcpcd-run-hooks(8), dhcpcd(8), if_nametoindex(3), fnmatch(3)

AUTHORS
     Roy Marples ⟨roy@marples.name⟩

BUGS
     Please report them to http://roy.marples.name/projects/dhcpcd

BSD			       January 28, 2010				   BSD
[top]

List of man pages available for aLinux

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
...................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net