Web-based Traffic and Security Network Traffic Monitoring
Pure Java Network Tools
MRTG - Multi Router Traffic Grapher
Monitor monthly internet Transmit and Receive bandwidth usage - Linux
NetFlow iptables module for Linux kernel
Watcher Traffic SNMP
Monitor Apache using SNMP
Open Source Managed File Transfer
Various TCP/IP servers, clients and network management tools
Framework for Man-In-The-Middle attacks
Nagios TCP traffic degradation detection plugin from link utilization
Bandwidth Monitoring Tool; Console SNMP traffic monitor