Roll Your Own Router With Shell Scripts

This project allows you to turn commodity PC hardware into a Linux based home router, while controlling every aspect of the router and it's tooling. It is designed to run on el9 (RHEL, CentOS Stream, Rocky, Alma). The intended audience is the advanced Linux user who wants extreme control and power over their router, and would prefer to use SSH and the command line to administer the router instead of a web interface such as DD-WRT, OpenWRT, etc..

Advantages

• Infinitely customizable, add additional features and configurations using Linux shell scripts, RPM spec files and /etc config files
• Automatically install the latest security updates
• Upgradable hardware, for example, you can replace your 1Gb/s NICs with 10Gb/s NICs
• Potentially much more CPU power than a standard passively cooled MIPS or ARM router

Disadvantages

• Not easy to bootstrap a new router, nor is it possible to write a comprehensive guide. You should be at least an intermediate level Linux user who is comfortable reverse engineering the default scripts and configurations before trying this, unless you are willing to be very patient and learn many new things. It is advisable to try it first on an old PC before spending money to build a new one.
• You will probably need to keep it plugged in to a keyboard, mouse and monitor while you are developing your own customizations. Eventually, you should be able to use it as a headless appliance
• May consume more power than a standard router, although anecdotally it seems that it consumes little power and generates little heat on an entry level Ryzen G series CPU.

Hardware

• Runs on any CPU architecture supported by el9 (x86_64, PowerPC, ARM).
• When choosing a motherboard and case form factor, take into account how many PCIe expansion cards you will need for NICs, wifi cards and other accessories
• If using as a wireless router, recommended to use a wifi card using a Qualcomm Atheros chip, for best compatibility with hostapd access points
• You will need at least one NIC for plugging into your modem, and additional NICs for any wired networking that you wish to do

BIOS Settings

You should, at a minimum, make the following BIOS settings if available:

• Computer always on after power failure -- Ensures that the router will stay running at all times, even after a temporary loss of power

Installing

NOTE: Only do this on the machine that you intend to use as a router, otherwise it will likely render your networking inoperable, and not easy to repair.

NOTE: When bootstrapping a new router for the first time, it is far easier to plug it into an existing router operating in a different subnet, and slowly move all of your devices over to the new router, before eventually plugging the new router directly into the modem (not applicable to all types of ISPs).

• Clone the git repository and cd into the directory.
• Update files/etc/ryor/config.yaml to match your hardware specs
• Update all of the config files in files/etc, or some can be deleted as desired from tools/rpm.spec
  • You may also need to modify some scripts such as create-network.sh
• Run tools/el9-deps.sh to install required dependencies
• Run make rpm to build the RPM, which can be installed with sudo dnf install ./$PACKAGE_NAME, or tools/reinstall.sh to update an existing installation.
• Reboot
• Check the logs, journalctl and systemctl status for any failures

Out of the Box Features

• wired networking
• wifi networking using hostapd, with radio scheduling to disable while you sleep and mac address randomization
• LAN switching using Linux bridge
• firewalld firewalling and port forwarding
• dnsmasq for DNS caching and DHCP
• sysctl settings to ensure the router will reboot on kernel panic or other kernel and hardware issues
• Automatic system updates and reboots
• systemd service management for the network configuration and all services

Tooling

There are scripts installed to /usr/local/bin that perform various adminstrative functions. See the individual scripts, which you may also want to customize.