PacketFence is an open-source package that provides network access control (NAC). Deployed in academic networks around the world, PacketFence is reliable, extremely configurable, and built upon unmodified open-source code (Fedora, LAMP, Perl, and Snort). PacketFence is designed to operate in heterogeneous environments and uses vendor-agnostic isolation techniques including DHCP scope changes and ARP cache manipulation ("passive" mode). No Cisco, no problem. Distributed as an RPM, PacketFence installs quickly and easily on RHEL and Fedora. When deployed in passive mode, PacketFence plugs into a switch like any other host - it's not even necessary to change your network configuration!