Since mid 2023 I have been running a Docker ISC Kea Image using base Docker Alpine Linux images, with S6 init system. (ISC Kea is a modern replacement for their DHCP.) The main DHCP server runs on my main server and I have an automatic fall over back up on my separate Linux router. I basically followed the Kea template Home Network of a Power User. I was never quite sure I had the automatic fall over back-up working. On 2023-01-02 I modified a configuration file on the primary server with a syntax error, 8 days later I notice millions of lines of errors on my log files. Sure enough the backup had simply been working. I fixed up the simple syntax error and the primary server took back over. Everything basically worked as expected.

ISC also has a project for a simple GUI interface primarily for Kea and basic for Bind9. There is apparently no Alpine package yet for Stork.

ISC-Kea seems to be provided in a number of packages

From IANA Service Name and Transport Protocol Port online Number Registry:

bootps    67   {tcp, udp}       Bootstrap Protocol Server (DHCP)
bootpc    68   {tcp, udp}       Bootstrap Protocol Client (DHCP)

The Kea Control Agent uses port 8000 by default, but that value can be manually defined in its configuration file. (Usually located at /etc/kea/kea-ctrl-agent.conf.) This port needs to be open and accessible on every server that hosts a Kea DHCP service and a Kea Control Agent.

This is a good case where the Docker network type needs to be set to host. The DHCP server needs to be directly on the host to function.

sudo nmap --script broadcast-dhcp-discover will test for DHCP servers on the same network. It will only report the first DHCP server discovered.

• Command line program to test DHCP service
• The Official Nmap Project Guide to Network Discovery and Security Scanning
• 5 scripts for getting started with the Nmap Scripting Engine

• kea-dhcp4 -t /app/dhcpv4.conf to test the kea-dhcp4 configuration files /app/dhcpv4.conf
• kea-dhcp4 -c /app/dhcpv4.conf to start kea dhcp4 using configuration file /app/dhcpv4.conf

Use of symlink, TL;DR;

• kea-dhcp4 -c /app/dhcpv4_plus.conf to start kea dhcp4 using configuration file /app/dhcpv4_plus.conf. This configuration file is designed to work with the kea control agent setup. Where as the basic configuration /app/dhcpv4_basic.conf is not.

• kea-ctrl-agent -t /app/kea-ctrl-agent.conf to test the kea-cont-agent configuration file /app/kea-ctrl-agent.conf
• kea-ctrl-agent -c /app/kea-ctrl-agent.conf to start the kea-cont-agent configuration file /app/kea-ctrl-agent.conf

• The Kea Control Agent

• Kea Logging Configuration

I have stored log files in the .config directory that is a Docker mounted volume for persistence and easy external viewing outside container. The following logs files can be seen.

• .config/log/kea-dhcp4-commands.log
• .config/log/kea-dhcp4-dhcpsrv.log
• .config/log/kea-dhcp4-leases.log
• .config/log/kea-dhcp4.log
• .config/log/kea-dhcp4-ha-hooks.log

• docker attach kptr-kea-1 to attach to running container
• kea-dhcp4 -v To check running version

• KPTree.net's bare metal implementation of dns - dhcp, based upon ISC Bind9 and DHCP on Debian 10 (was originally Ubuntu).
• ISC documentation
  • Template: Home Network of a Power User
  • Using Official ISC Packages for Kea
  • Kea Configuration Introduction
  • Kea Configuration for Small Office or Home Use
  • Install and run KEA DHCP with Stork on Debian 11
  • JonasAlfredsson / docker-kea