--- name: "dhcpcd-run-hooks" section: "8" platform: "linux" package: "dhcpcd" version: "10.5.2-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/dhcpcd-run-hooks" --- # dhcpcd-run-hooks(8) DHCP client configuration script ## NAME **dhcpcd-run-hooks** – DHCP client configuration script ## DESCRIPTION **dhcpcd-run-hooks** is used by [dhcpcd(8)](/dhcpcd/8.md) to run any system and user defined hook scripts. System hook scripts are found in */usr/lib/dhcpcd/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**, **--variables** argument. 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 generally 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. - NOCARRIER\_ROAMING 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 server. - RELEASE \| RELEASE6 dhcpcd has released the lease. - 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 \| TIMEOUT6 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 normally 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. ## ENVIRONMENT **dhcpcd** will clear the environment variables aside from $PATH. The following 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 or down. - $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 preference. - $if\_configured true if dhcpcd has configured the interface otherwise false. - $if\_up true if the interface is up, otherwise false. This is more than IFF\_UP and may not be equal. - $if\_down true if the interface is down, otherwise false. This is more than IFF\_UP and may not be equal. - $af\_waiting Address family waiting for, as defined in [dhcpcd.conf(5)](/dhcpcd.conf/5.md). - $profile the name of the profile selected from [dhcpcd.conf(5)](/dhcpcd.conf/5.md). - $new\_delegated\_dhcp6\_prefix space-separated list of addresses assigned from delegated prefixes. ## FILES When **dhcpcd-run-hooks** runs, it loads */etc/dhcpcd.enter-hook*, any scripts found in */usr/lib/dhcpcd/dhcpcd-hooks* in lexical order, then finally */etc/dhcpcd.exit-hook*. ## SEE ALSO [dhcpcd(8)](/dhcpcd/8.md) ## AUTHORS Roy Marples ⟨*roy@marples.name*⟩ ## BUGS Please report them to **https://roy.marples.name/projects/dhcpcd** ## SECURITY CONSIDERATIONS **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.