fwlogwatch is a packet filter and firewall log analyzer with support for Linux ipchains, Linux netfilter/iptables, Solaris/BSD/HP-UX/IRIX ipfilter, Cisco IOS, Cisco PIX/ASA, Netscreen, Elsa Lancom router, and Snort IDS log files. It can output its summaries in text and HTML and has a lot of options. fwlogwatch also features a realtime anomaly response capability with a Web interface.
The MiniUPnP project is a library and a daemon. The library is aimed to enable applications to use the capabilities of a UPnP Internet Gateway Device present on the network to forward ports. The daemon adds the UPnP Internet Gateway Device functionality to a NAT gateway running OpenBSD/NetBSD/FreeBSD/Solaris with PF/IPF or Linux 2.4.x/2.6.x with netfilter. One of its most interesting features is to enforce some permissions to allow or deny redirections, bringing some security to UPnP. Newer versions also support the NAT-PMP protocol from Apple.
Firewall Builder consists of a GUI and set of policy compilers for various firewall platforms. It helps users maintain a database of objects and allows policy editing using simple drag-and-drop operations. The GUI and policy compilers are completely independent, which provides for a consistent abstract model and the same GUI for different firewall platforms. It currently supports iptables, ipfilter, ipfw, OpenBSD pf, Cisco PIX and FWSM, and Cisco routers access lists.
vpnd is a daemon which connects two networks on network level either via TCP/IP or a (virtual) leased line attached to a serial interface. All data transfered between the two networks are encrypted using the unpatented free Blowfish encryption algorithm with a key length of up to 576 bits (may be downgraded to a minimum of 0 bits to suit any legal restrictions).
Pound is a reverse HTTP proxy, load balancer, and SSL wrapper. It proxies client HTTPS requests to HTTP backend servers, distributes the requests among several servers while keeping sessions, supports HTTP/1.1 requests even if the backend server(s) are HTTP/1.0, and sanitizes requests.
m0n0wall is an all-in-one firewall software package that is based on FreeBSD. It is geared towards embedded PCs, but it also works on standard PCs. It includes an easy-to-use Web interface like commercial firewall boxes do. PHP is used instead of shell scripts, and the entire system configuration is stored in a single XML-formatted file. There is support for VPN, traffic shaping, captive portal, VLANs, and more.
LFT (Layer Four Traceroute) is a sort of "traceroute" that often works much faster than the commonly-used Van Jacobson method and goes through many configurations of packet-filter based firewalls. More importantly, LFT implements numerous other features, including TCP, UDP, or ICMP-based traces, AS number lookups through several reliable sources, loose source routing, netblock name lookups, and more. LFT also distinguishes between layer-4 protocols, which make its statistics slightly more realistic, and gives a savvy user the ability to trace protocol routes, not just layer-3 hops.