repository·master·Indexed 19 days ago
https://github.com/networkconfiguration/dhcpcddhcpcd is a DHCP (v4/v6) and IPv4LL (ZeroConf) client designed to automatically configure network interfaces. This documentation covers daemon configuration via dhcpcd.conf, build instructions using the configure script, binary size reduction options, cross-compilation, and the use of network event hooks.
dhcpcd is a DHCP and DHCPv6 client, as well as an IPv4LL (ZeroConf) client. It is designed to run on a machine to silently configure network settings for attached networks with minimal manual configuration.
For desktop users, dhcpcd-ui (Network Configurator) is available as a notification area application to monitor network state and provide a configuration dialog for wireless networks.
dhcpcd-4.To enable libpcap support, use the --with-libpcap flag. This is recommended for systems that lack the necessary kernel hooks for packet capture.
./configure --with-libpcapdhcpcd uses a POSIX shell script ./configure for building, which functions similarly to GNU configure. Note that some build-time warnings are expected on most platforms (except DragonFlyBSD and NetBSD).
To build, run the configure script followed by your preferred build command (typically make).
./configureIf you are building for installation media or environments where disk space is limited, you can reduce the binary size using several options:
--small: Enables a reduced feature set (removes non-essential options from dhcpcd-definitions.conf, logfile option, DHCPv6 Prefix Delegation, and IPv6 address announcement).--disable-inet: Removes the IPv4 stack.--disable-inet6: Removes the IPv6 stack.--disable-auth: Removes authentication features.--disable-arp: Removes ARP support.--disable-arping: Removes arping support.--disable-ipv4ll: Removes IPv4 Link Local support.--disable-dhcp6: Removes DHCPv6 support.--disable-privsep: Removes privilege separation.--disable-embedded: Moves the embedded extended configuration from the binary to an external file (LIBEXECDIR/dhcpcd-definitions.conf). Note that if this file cannot be loaded at runtime, dhcpcd will only decode DHCP/DHCPv6 options explicitly defined in /etc/dhcpcd.conf../configure --smallBy default, dhcpcd uses its own internal cryptographic routines. To use libcrypto from OpenSSL instead, use the --with-openssl flag.
./configure --with-opensslIf you need to import dhcpcd into another source control system, use the make targets:
import: Imports the full source tree.import-src: Imports only the necessary source files and documentation.Both targets support the DESTDIR variable to specify the installation directory. If unset, it defaults to /tmp/dhcpcd-$VERSION.
make DESTDIR=/usr/src/contrib/dhcpcd import-srcWhen upgrading dhcpcd, be aware of changes to default directory locations:
/var/db/dhcpcd (previously /var/db). Files dhcpcd.duid and dhcpcd.secret are stored here instead of /etc./var/run/dhcpcd (previously /var/run), and the dhcpcd prefix has been removed from files within that directory.When cross-compiling for a different OS than your host, use the --target flag to specify the target platform.
For MMU-less systems where fork() is unavailable, use --disable-fork. This automatically enables the --no-background flag and prevents the --background flag from working.
./configure --target=sparc-sun-netbsd5.0
./configure --disable-forkHooks allow dhcpcd to perform actions during network events.
Default Hooks:
01-test20-resolv.conf30-hostnameAdditional Hooks:
Some hooks (like 10-wpa_supplicant, 15-timezone, and 29-lookup-hostname) are located in $(datadir)/dhcpcd/hooks and must be manually copied to $(libexecdir)/dhcpcd-hooks to be active.
Adding Hooks:
You can specify a hook to be included during configuration using the -with-hook flag.
./configure -with-hook=ntp.confLinux SECCOMP behavior depends on the relationship between libc and the kernel. If a libc update introduces a syscall that dhcpcd's SECCOMP filter does not recognize, dhcpcd may break.
To resolve this, you can use --disable-seccomp. This allows dhcpcd to still use a POSIX resource-limited sandbox via privilege separation without the SECCOMP filter.
./configure --disable-seccompConfiguration options for the dhcpcd daemon are placed in /etc/dhcpcd.conf. For a complete list of available options, refer to the dhcpcd.conf(5) man page.
Below is a sample configuration demonstrating common use cases such as hostname reporting, DUID usage, and persistent interface configuration.
# A sample configuration for dhcpcd.
# See dhcpcd.conf(5) for details.
# Allow users of this group to interact with dhcpcd via the control socket.
#controlgroup wheel
# Inform the DHCP server of our hostname for DDNS.
hostname
# Use the hardware address of the interface for the Client ID.
#clientid
# or
# Use the same DUID + IAID as set in DHCPv6 for DHCPv4 ClientID as per RFC4361.
# Some non-RFC compliant DHCP servers do not reply with this set.
# In this case, comment out duid and enable clientid above.
duid
# Persist interface configuration when dhcpcd exits.
persistent
# Rapid commit support.
# Safe to enable by default because it requires the equivalent option set
# on the server to actually work.
option rapid_commit
# A list of options to request from the DHCP server.
option domain_name_servers, domain_name, domain_search, host_name
option classless_static_routes
# Respect the network MTU. This is applied to DHCP routes.
option interface_mtu
# Most distributions have NTP support.
#option ntp_servers
# A ServerID is required by RFC2131.
require dhcp_server_identifier
# Generate SLAAC address using the Hardware Address of the interface
#slaac hwaddr
# OR generate Stable Private IPv6 Addresses based from the DUID
slaac private