conntrack-tools is a set of userspace tools for Linux that allow system administrators to interact with the Connection Tracking System, the module which provides stateful packet inspection for iptables. It includes the userspace daemon conntrackd and the commandline interface conntrack.
The GNOME NetworkManager is a set of co-operative tools that make networking simple and straightforward. Whether wireless or wired, NetworkManager allows you to quickly move from one network to another: once a network has been configured and joined once, it can be detected and re-joined automatically at a later date. It was designed to auto-detect as much information as possible, seamlessly switches connections when necessary, and provides immediate feedback of the network state to users and applications.
The ROHC library provides an easy and robust way for applications to reduce their bandwidth usage on network links with limited capacity or expensive costs. Headers of network packets are compressed with the ROHC protocol and algorithms. The ROHC protocol is very efficient for compressing VoIP streams which use RTP as a transport protocol. ROHC is also suitable for compressing IP-only (IPv4 or IPv6) flows, UDP flows, and many others.
RCP100 is a modular router control plane for Linux platforms. It can be used as a standalone router, or it can be deployed as an embedded router in a virtualized environment. The modular architecture allows rapid introduction of new features and functionality, including support for custom hardware. It features a command line interface, Web interface, Telnet, FTP, and TFTP access, an NTP client and server, a DNS proxy cache, a DHCP relay, static routes, blackhole routes, static ARP, proxy ARP, RIP version 2 (RFC 2082, RFC 2453), OSPF version 2 (RFC 2328), and Access Control Lists.
Sanewall is a firewall builder for Linux that uses an elegant language abstracted to just the right level. This makes it powerful and easy to use, audit, and understand. It allows you to create very readable configurations even for complex stateful firewalls. Sanewall can be used for almost any purpose, including control of any number of internal/external/virtual interfaces, control of any combination of routed traffic, setting up DMZ routers and servers, all kinds of NAT, providing strong protection (flooding, spoofing, etc.), transparent caches, source MAC verification, blacklists, and whitelists. Newer versions abstract the differences between IPv4 and IPv6, allowing you to define a common set of rules for both, while permitting specific rules for each as you need. Sanewall is a fork of FireHOL and can make use of existing FireHOL configurations.