Addns.pl is a self-contained DynDNS update client for DynDNS.org (and possibly others). It supports a variety of IP detection methods including external webcheck/router pages. It also supports multiple configurations and hostnames, smart abuse prevention, and custom/static/dynamic DNS, and can run as a daemon, commandline options only, or with a configuration file.
Angst is an active sniffer, based on libpcap and libnet. It dumps into a file the payload of all the TCP packets received on the specified ports. It implements two methods for active sniffing. Angst is able to monitor ARP requests, and after enabling IP forwarding on the local host, it sends ARP replies mapping all IPs to the local MAC address. Also, it can flood the local network with random MAC addresses (like macof), causing switches to send packets to all ports.
Balance is a simple but powerful generic TCP proxy with round-robin load balancing and failover mechanisms. Its behavior can be controlled at runtime using a simple command line syntax. Balance supports IPv6 on the listening side, which makes it a very useful tool for IPv6 migration of IPv4 only services and servers.
bcnu is a Web-based system management tool which delivers information on the status of networked systems in a simple and easy-to-use manner. It uses a web browser to display information about hosts in a tabular form. Historical information can be held indefinitely, and there is a powerful query tool available to interrogate it. Client systems can run an agent which logs information back to a central system. An agent scheduler is integrated to allow agents to be run at different intervals. Standard agents include ftp, http, disk space, logfiles, processes, and more.
Big Brother is a combination of monitoring methods. Unlike SNMP where information is just collected and devices polled, Big Brother is designed in such a way that each local system broadcasts its own information to a central location. Simultaneously, Big Brother also polls all networked systems from a central location. This creates a highly efficient and redundant method for proactive network monitoring.
DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
dhcpcd is an RFC2131 compliant DHCP client. It is fully featured and yet lightweight: the binary is 60k as reported by size(1) on Linux i386. It has support for duplicate address detection, IPv4LL, carrier detection, and a merged resolv.conf and ntp.conf for which other DHCP clients require third party tools.