QDPF was written to solve the problem of exposing internal services to the Internet. It runs on machines which bridge two networks and forwards TCP/IP packets from one to the other. Its main use is to expose corporate or Intranet services to the Internet, by running it on an intervening machine. TCP sessions can also be followed in detail using the 'trace' option. QDPF is a Java console application.
pks-commands.php3 allows your Web server to search and add PGP/GPG keys from the public keys out there. It takes the TCP 11371 port connection and does it all on the web server. It is good in environments where the client machines are unable to get to arbitrary TCP ports (such as behind tightened firewalls).
SING stands for 'Send ICMP Nasty Garbage.' It is a tool that sends ICMP packets fully customized from command line. Its main purpose is to replace and complement the ping command, adding certain enhancements as fragmentation; send and receive spoofed packets; send many ICMP information types (echo as the old ping, address mask, timestamp, and router discovery) and errors (redirect, unreach, and time exceeded); and send monster packets. It also supports loose and strict source routing and record routing.
fireparse is an ADMLogger plugin that emails a report of all packets that have been logged by the kernel's packet filtering subsystem (iptables/netfilter or ipchains). The report includes source and destination ports, direction, logged packet count, matched rule, and fully resolved host names (if available). The email report can be formatted to plain text or a colored HTML table.
tsocks provides transparent network access through a SOCKS version 4 or 5 proxy (usually on a firewall). tsocks intercepts the calls applications make to create TCP connections and determines if they can be directly accessed or need the SOCKS server. If they need the SOCKS server they connection is negotiated with the server transparently to the application. This allows existing applications to use SOCKS without recompilation or modification. tsocks is a wrapper library for the libc connect() call.
FrazierWall Linux is a single floppy distribution Linux firewall that is based on the Linux Router Project. It is designed for use with ethernet base internet connections (such as cable modems or xDSL lines). It allows you to share such a connection with several other computers on a LAN. It is easy to setup and maintain, and is available in a Linux configurable software version.