NetXMS is a network monitoring and management system with a modular architecture. It can be used for monitoring an entire IT infrastructure, starting with SNMP-capable hardware (like switches and routers) and ending with applications on servers. The system has a three-tier architecture; the information is collected by monitoring agents (either its own agents or SNMP agents) and delivered to the monitoring server for processing and storing, where it can be accessed by using the management console. It features centralized configuration and centralized agent upgrades.
sslh accepts connections in HTTP, HTTPS, SSH, OpenVPN, tinc, XMPP, or any other protocol that can be tested using a regular expression, on the same port. This makes it possible to connect to any of these servers on port 443 (e.g. from inside corporate firewalls, which almost never block port 443) while still serving HTTPS on that port. sslh supports IPv6, privilege dropping, transparent proxying, and much more.
vnStat is a console-based network traffic monitor that keeps a log of hourly, daily, and monthly network traffic for the selected interface(s). It uses the network interface statistics provided by the kernel as information source. This means that vnStat won't actually be sniffing any traffic, and also ensures light use of system resources.
The NET-SNMP (formerly UCD-SNMP) package contains various tools relating to the Simple Network Management Protocol including an extensible agent, an SNMP library, tools to request or set information from SNMP agents, tools to generate and handle SNMP traps, a version of the unix 'netstat' command using SNMP and a Tk/perl mib browser. It was originally based on the Carnegie Mellon University SNMP implementation (version 188.8.131.52), but has been greatly enhanced, ported and fixed and barely resembles the original package anymore.
xllmnrd is an IPv6 LLMNR responder daemon (primarily for GNU/Linux operating systems). It allows Microsoft Windows clients to get the IPv6 address of a server on the same local network without any DNS configuration and effectively complements IPv4-only NetBIOS name resolution provided by Samba.