net-status-monitor is a simple console script to test whether Internet connectivity is working. If it is, the script tells you the external IP address (in case your dynamic DNS provider is down). If not, it tries to find the point where the connectivity fails. The output is quite simple, so you can put it on your grandmother's PC. "Just tell me what the read line says" should give you enough information.
MyConnection Server is broadband testing software which measures connections for bandwidth speeds and connection quality for time critical applications such as VoIP, Video conferencing, and IPTV. It helps organizations assess networks for deployment of new/additional services and identify and resolve last mile customer connectivity problems with little need for the customer to assist in the resolution process. A network route testing component details the path of the connections and where packet loss and latency occur, including discovery of multiple routes to a destination. Remote Test Agents enable technical staff to customize and interactively manage the bandwidth testing process and perform extended quality testing over hours or days to address and resolve intermittent problems as required. Satellite Servers establish additional connection testing points at the application edge to accurately test actual application network paths.
liboping is a C library for measuring network latency using ICMP echo requests. It can send to and receive packets from multiple hosts in parallel, which is nice for monitoring applications. Both IPv4 and IPv6 are supported transparently for the programmer and user. A program called oping is included to show the simplicity and potential of the library and provide the functionality at the command line.
ICPLD (Internet Connection Performance Logging Daemon) is a connection monitor that sends ICMP requests to IP addresses of your choice and monitors if your machine has a working network connection. It logs failed attempts to reach the hosts, and will stamp a log as soon as a reply is received. It keeps track of when and for how long the connection was unavailable and records both total down time and each occasion of interrupted connection. It supports IPv6 and can execute a command whenever a connection goes up or down, which is useful for alerting users.
MCS MyVoIP very accurately measures the quality and performance of Internet connections for Voice over IP (VoIP) usage by simulating UDP voice data traffic between a server and browser clients. Connections are tested for jitter and packet loss and rated for the supported level of sound quality. The VoIP test can be set to various codecs or customized by packet size, packet rate, and test length. The test can further be combined with a bandwidth speed test or network route diagnostics for more in-depth connection analysis.
JSTUN is a STUN (Simple Traversal of UDP (User Datagram Protocol) through NAT (Network Address Translation)) implementation. STUN provides a means for applications to discover the presence and type of firewalls or NATs between them and the public Internet. In the presence of a NAT, STUN can also be used by applications to learn the public Internet Protocol (IP) address assigned to the NAT.
The main purpose of LoFiMo is, as the name states, to monitor log files. It does this in real time, i.e. shows the contents of log files as they are changing. The user can connect to LoFiMo with a Web browser or use the console for plain text output. When using a Web browser, the output can be formatted with cascading stylesheets, which the user can define. Thus, it is possible to highlight certain log entries with different colors and fonts. It is also possible to play sounds or execute commands (send an email, play sound with a custom player, etc.) when a log entry matches a filter. LoFiMo can parse Apache style log files and syslog style log files. Among others, there are filters that can parse iptables logs and merge multiple log lines of Postfix into a single one.
dietsniff is a tiny tool for analyzing traffic on a network. It's not intended to replace well-known tools like tcpdump or ethereal. It's intended for the case when a small and especially static sniffer is required. Accordingly, it's also by far not that powerful, and is also bound to Linux as a platform. While it doesn't use or need the libpcap, it produces pcap-logs that can be analyzed by more sophisticated tools like tcpdump or Ethereal.