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DHCPCD-RUN-HOOKS(8) NetBSD System Manager's Manual DHCPCD-RUN-HOOKS(8)
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dhcpcd-run-hooks -- DHCP client configuration script
dhcpcd-run-hooks is used by dhcpcd(8) to run any system and user defined
hook scripts. System hook scripts are found in /libexec/dhcpcd-hooks and
the user defined hooks are /etc/dhcpcd.enter-hook. and
/etc/dhcpcd.exit-hook. The default install supplies hook scripts for
configuring /etc/resolv.conf and the hostname. Your distribution may
have included other hook scripts to say configure ntp or ypbind. A test
hook is also supplied that simply echos the dhcp variables to the console
from DISCOVER message.
The hooks scripts are loaded into the current shell rather than executed
in their own process. This allows each hook script, such as
/etc/dhcpcd.enter-hook to customise environment variables or provide
alternative functions to hooks further down the chain. As such, using
the shell builtins exit, exec or similar will cause dhcpcd-run-hooks to
exit at that point.
Each time dhcpcd-run-hooks is invoked, $interface is set to the interface
that dhcpcd is run on and $reason is set to the reason why
dhcpcd-run-hooks was invoked. DHCP information to be configured is held
in variables starting with the word new_ and old DHCP information to be
removed is held in variables starting with the word old_. dhcpcd can
display the full list of variables it knows about by using the -V,
Here's a list of reasons why dhcpcd-run-hooks could be invoked:
PREINIT dhcpcd is starting up and any pre-initialisation
required should be performed now.
CARRIER dhcpcd has detected the carrier is up. This is gener-
ally just a notification and no action need be taken.
NOCARRIER dhcpcd lost the carrier. The cable may have been
unplugged or association to the wireless point lost.
dhcpcd lost the carrier but the interface configuration
is persisted. The OS has to support wireless roaming
or IP Persistence for this to happen.
INFORM | INFORM6 dhcpcd informed a DHCP server about its address and
obtained other configuration details.
BOUND | BOUND6 dhcpcd obtained a new lease from a DHCP server.
RENEW | RENEW6 dhcpcd renewed its lease.
REBIND | REBIND6 dhcpcd has rebound to a new DHCP server.
REBOOT | REBOOT6 dhcpcd successfully requested a lease from a DHCP
DELEGATED6 dhcpcd assigned a delegated prefix to the interface.
IPV4LL dhcpcd obtained an IPV4LL address, or one was removed.
STATIC dhcpcd has been configured with a static configuration
which has not been obtained from a DHCP server.
3RDPARTY dhcpcd is monitoring the interface for a 3rd party to
give it an IP address.
TIMEOUT dhcpcd failed to contact any DHCP servers but was able
to use an old lease.
EXPIRE | EXPIRE6 dhcpcd's lease or state expired and it failed to obtain
a new one.
NAK dhcpcd received a NAK from the DHCP server. This
should be treated as EXPIRE.
RECONFIGURE dhcpcd has been instructed to reconfigure an interface.
ROUTERADVERT dhcpcd has received an IPv6 Router Advertisement, or
one has expired.
STOP | STOP6 dhcpcd stopped running on the interface.
STOPPED dhcpcd has stopped entirely.
DEPARTED The interface has been removed.
FAIL dhcpcd failed to operate on the interface. This nor-
mally happens when dhcpcd does not support the raw
interface, which means it cannot work as a DHCP or
ZeroConf client. Static configuration and DHCP INFORM
is still allowed.
TEST dhcpcd received an OFFER from a DHCP server but will
not configure the interface. This is primarily used to
test the variables are filled correctly for the script
to process them.
dhcpcd will clear the environment variables aside from $PATH. The fol-
lowing variables will then be set, along with any protocol supplied ones.
$interface the name of the interface.
$protocol the protocol that triggered the event.
$reason as described above.
$pid the pid of dhcpcd.
$ifcarrier the link status of $interface: unknown, up
$ifmetric $interface preference, lower is better.
$ifwireless 1 if $interface is wireless, otherwise 0.
$ifflags $interface flags.
$ifmtu $interface MTU.
$ifssid the SSID the interface is connected to.
$interface_order A list of interfaces, in order of prefer-
$if_up true if the interface is up, otherwise
false. This is more than IFF_UP and may not
$if_down true if the interface is down, otherwise
false. This is more than IFF_UP and may not
$af_waiting Address family waiting for, as defined in
$profile the name of the profile selected from
$new_delegated_dhcp6_prefix space-separated list of delegated prefixes.
When dhcpcd-run-hooks runs, it loads /etc/dhcpcd.enter-hook, any scripts
found in /libexec/dhcpcd-hooks in lexical order, then finally
Roy Marples <email@example.com>
Please report them to
dhcpcd will validate the content of each option against its encoding.
For string, ascii, raw or binhex encoding it's up to the user to validate
it for the intended purpose.
When used in a shell script, each variable must be quoted correctly.
NetBSD 10.99 August 31, 2022 NetBSD 10.99