dhcpcd

DHCP and DHCPv6 client daemon

TLDR

Obtain a lease on a specific interface

$ sudo dhcpcd [eth0]

Release all address leases and exit

$ sudo dhcpcd -k

Request new leases (rebind)

$ sudo dhcpcd -n

Configure IPv4 only

$ sudo dhcpcd -4 [eth0]

Configure IPv6 only

$ sudo dhcpcd -6 [eth0]

Test mode (don't configure, just print variables)

$ sudo dhcpcd -T [eth0]

dhcpcd is a DHCP and DHCPv6 client daemon that automatically configures network interfaces. It obtains IP addresses, default routes, and DNS servers from DHCP servers on the network, and can also process IPv6 Router Advertisements for stateless autoconfiguration.The daemon runs in the background managing network configuration as interfaces come up and down. It handles lease renewal, rebinding, and release operations automatically. Configuration hooks allow running custom scripts when network state changes.dhcpcd is commonly used as the default network configuration tool on many Linux distributions, particularly those without NetworkManager. It's lightweight, follows RFC standards closely, and integrates well with embedded and server environments.

PARAMETERS

-k, --release

Release current leases and exit

-n, --rebind

Request new leases (rebind)

-x, --exit

Exit daemon

-d, --debug

Debug mode (don't fork)

-B, --nobackground

Don't run in background

-4, --ipv4only

Only configure IPv4

-6, --ipv6only

Only configure IPv6

-b, --background

Background immediately

-S, --static value

Configure a static DHCP value (e.g., ipaddress, routers, domainname_servers)

-s, --inform address

Send DHCP INFORM instead of DISCOVER/REQUEST

-T, --test

Test mode, don't configure interfaces

CONFIGURATION

/etc/dhcpcd.conf

Main configuration file controlling interface behavior, static addresses, hooks, and client options.

INSTALL

sudo apt install dhcpcd-base

sudo dnf install dhcpcd

sudo pacman -S dhcpcd

sudo apk add dhcpcd

sudo zypper install dhcpcd

nix profile install nixpkgs#dhcpcd

CAVEATS

May conflict with NetworkManager or systemd-networkd. Configuration file is /etc/dhcpcd.conf. Requires root privileges.