There are many free open source router and firewall solutions for small businesses --and even a few options for enterprises. Many of these also offer other LAN services, such as a VPN server, hotspot gateway and captive portal. This ServerWatch report, by Eric Geier, looks at 7 open and free network servers.

3 Open and Free Network Servers

Here, we'll discover some free and open router projects, covering those suitable for small businesses, medium-sized, and even enterprise-level comparable to Cisco and Juniper.

1.  DD-WRT  

DD-WRT is a Linux-based firmware replacement for consumer-level wireless routers, suitable for use by small businesses. In addition to serving as an Internet gateway and network router, it also features an OpenVPN server and client, SSH server, FTP server, and hotspot and captive portal services. Other general features support multiple SSIDs, VLANs, and the ability to customize the startup and firewall scripts.

You can check their router database to see which wireless routers are supported and the DD-WRT variants they support. They also offer a Wiki with a FAQ and installation and configuration help. Some routers can easily be flashed with the aftermarket firmware via the router's web-based control panel while others require you to connect via TFTP. They even offer hardware specific instructions. 2. RouterOS

RouterOS is the Linux-based operating system used by the RouterBOARD product line by MikroTik. It can also be installed onto and run from X86-based PCs and servers. Along with the basic firewall and network services, it supports many VPN protocols, RADIUS server and client, TFTP server, and a hotspot gateway. Additionally, it offers various routing protocols and multiple wireless modes.

A basic feature-set of RouterOS is freely available and additional functionality is offered via multiple license levels.

You can install RouterOS onto a machine via a bootable install disc or use the Netinstall utility to install onto a secondary from within Windows and then put into your router PC or server. There are several configuration mediums: local access, serial console, Telnet, SSH access, GUI configuration tool called Winbox, and web-based interface. You can even build your own control application with their API programming interface.

3.  Vyatta  

Vyatta provides a free community version of its enterprise-level network OS, comparable to commercial solutions such as Cisco and Juniper. It's a Debian-based Linux distribution that can run on X86 platforms or on VMware, Citrix XenServer, Xen, KVM, and other hypervisors. In addition to the routing protocols and other typical network services, it provides web filtering and IPsec Site-to-Site VPN, Remote Access VPN, and OpenVPN.

Vyatta is available to download as a Live CD or virtualization image as 32-bit and experimental 64-bit. They also offer comprehensive documentation