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.
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).
GKrellM is a GTK-based stacked monitor program that charts SMP CPUs, disks, load, active net interfaces, and internet connections. There are also builtin monitors for memory and swap, file systems with mount/umount feature, mailbox checking including POP3 and IMAP, clock/calendar, laptop battery, sensors (temperatures, voltages, and fans), and uptime. It has LEDs for the net monitors and an on/off button and online timer for PPP. There is a GUI popup for configuration, plugin extensions can be installed, and many themes are available. It also features a client/server monitoring capability.
iplog is a TCP/IP traffic logger. Currently, it is capable of logging TCP, UDP, and ICMP traffic. iplog is able to detect TCP port scans, TCP null scans, FIN scans, UDP and ICMP "smurf" attacks, bogus TCP flags, TCP SYN scans, TCP "Xmas" scans, ICMP ping floods, UDP scans, and IP fragment attacks. iplog is able to run in promiscuous mode and monitor traffic to all hosts on a network. iplog uses libpcap to read data from the network and can be ported to any system that supports pthreads and on which libpcap will function.
LCDproc is a utility to drive one or more LCD (and LCD-like) devices attached to a host. It is comprised of a server, which uses a modular device driver system to control attached displays, and one or more clients to gather data as appropriate and send screen data to the server. The included client displays a multitude of system statistics (CPU/memory/disk usage, uptime, date and time, temperature, etc.). Multiple clients can connect to the server simultaneously, and clients can set priorities on the screens they provide to influence in what order items are displayed. This facility can also be used to "pop" critical screens (such as an entry from syslog from a log-watching client). All functionality is implemented in userland. Support for many display devices and several platforms (Linux, *BSD, and Solaris at least) is included.
Heartbeat is a full-function high-availability system for Linux and other POSIX-like OSes. It monitors services and restarts them on errors. When managing a cluster (more than 1 machine), it will also monitor the members of the cluster and begin recovery of lost services in less than a second. It runs over serial ports and UDP broadcast/multicast, as well as OpenAIS multicast. It is easily adapted to different interconnect media and protocols. When used in a cluster, it can operate using shared disks, data replication, or no data sharing. Versions starting with 2.0 are comparable to any commercial HA package, providing resource monitoring, larger clusters, and detailed dependency information.
mod_backhand is a load balancing module for Apache. It provides per-request HTTP redirection within a heterogeneous Apache server cluster. Each request is processed and run through a set of "candidacy functions" to determine which server is best suited to respond. The request is then proxied to that server. Facilities are in place to allow you to write your own dynamically loadable decision making algorithms. Everything about the request and the current availability of resources can be used in the decision-making process.
Monit is a utility for managing and monitoring processes, programs, files, directories, and devices on a Unix system. It conducts automatic maintenance and repair and can execute meaningful causal actions in error situations. It can be used to monitor files, directories, and devices for changes, such as timestamps changes, checksum changes, or size changes. It is controlled via an easy to configure control file based on a free-format, token-oriented syntax. It logs to syslog or to its own log file and notifies users about error conditions via customizable alert messages. It can perform various TCP/IP network checks, protocol checks, and can utilize SSL for such checks. It provides an HTTP(S) interface for access.
Nets is a flexible and extensible network inventory and asset management system that works on all Unix and Windows platforms, and works with most SQL databases. Its complete GUI allows you to maintain details of your entire network, from network links down to interfaces and routers. It assists in provisioning, costing, reporting, and maintaining network details. It includes a network browser, an extension API, and plugins for IP address map visualisation, reports, schematics.