This list contains Linux distributions or Unix distributions specifically designed to be used as the operating system of a machine acting as a router and/or a firewall.
- BrazilFW
- BrazilFW is a Router/firewall distribution based on Coyote Linux
- Cflinux
- Cflinux is intended to be a small, embedded linux based system, mostly usable for firewall (Linux kernel 2.4 with iptables), router (ripd, ospfd, even bgpd from quagga), 802.11a/b/g access point (hostap and madwifi drivers), IPSEC gateway (openswan), PPPoE server (with radius authentication, kernel PPPoE), PPTP access servers
- CiscoASA
- Cisco ASA 8.x.x is Linux distribution used in Cisco ASA Security Appliances. An article in German, describing the contents of the package
- ClarkConnect
- Router/firewall distribution
- Collax Business Server
- A Router/firewall & web-, email- and database server distribution
- Collax Security Gateway
- A specialized Router/firewall/IDS/IPS server distribution
- Coyote Linux
- Router/firewall distribution
- Devil-Linux
- firewall/router/server distribution running from CD
- DD-WRT
- Embedded firewall distribution
- eBox
- Router/Firewall and NAS/PDC
- Eisfair
- small easy to install server
- Endian Firewall
- Unified Threat Management distribution (Router/Firewall, Gateway Anti-Spam & Anti-Virus for Web, FTP and Email, Hotspot functionality)
- EnGarde Secure Linux
- A Router/firewall & web-, email- and database server distribution
- Fli4l
- a single floppy ISDN, DSL and Ethernet-Router
- floppyfw
- floppyfw is a router with the advanced firewall-capabilities in Linux that fits on one single floppy disc.
- FREESCO
- a free replacement for proprietary routers supporting up to 10 network cards and up to 10 modems.
- Gibraltar
- Router/firewall distribution.
- IPCop
- Router/firewall distribution
- IPFire
- Router/firewall/homeserver distribution with webbased paketmanager
- LEAF Project
- a customizable embedded Linux network appliance used as an Internet gateway, router, firewall, and wireless access point.
- Ideco Gateway
- Advanced Router/Firewall distro
- OpenWrt
- Modular embedded distribution for ARM, MIPS, PPC and x86 devices.
- M0n0wall
- A Router/firewall distribution based on FreeBSD.
- PfSense
- A free, open source customized distribution of FreeBSD tailored for use as a firewall and router.
- PyramidLinux
- A wireless router distribution for x86 embedded systems.
- redWall
- Router/firewall distribution
- Sentry Firewall
- A firewall, server or intrusion detection system distribution
- SME Server
- A Router/firewall[citation needed] & web-, file-, email- and database server distribution based on CentOS
- SmoothWall
- Router/firewall distribution
- The Linux Router Project
- Router distribution (Defunct as of 2003)
- Trustix
- Router/firewall distribution with SSH and GCC included if desired.(Defunct as of jan 2009)
- Untangle
- GPLv2 Firewall & Router that runs 12 open source applications including Spam Blocker, Virus Blocker, Web Filter, OpenVPN & More.
- Vyatta
- Enterprise-class routing, security and traffic management with simple-to-use interfaces designed as a network operating system that runs on Intel/AMD as well in virtual environments.
- Zeroshell
- Web administrable router/firewall live CD with QoS features. It is also able to act as a Wi-Fi Access Point with advanced features such as the Multiple SSID and 802.1x RADIUS Authentication. Zeroshell supports VLAN trunking (802.1q), bridging and WAN load balancing and failover features.