Generating much excitement back in 2018 was bpfilter for the potential to better Linux's firewall and packet filtering by making it more robust and performance. Recently work on this BPF-based firewall solution was renewed and the performan...
Computer researchers in Europe are developing a new prototype architecture for halting distributed denial-of-service (DDOS) attacks, where a barrage of traffic is directed at a Web site or server to shut it down.The Diadem Firewall deploys both hardware and software on the edge of a provider's network rather than within, said Georg Carle, chair of the computing and Internet department at the University of T
"Packet-Filtering Concepts," covers the background ideas and concepts behind a packet-filtering firewall. Each built-in rule chain has its own default policy. Each rule can apply not only to an individual chain, but also to a specific network interface, message protocol type (such as TCP, UDP, or ICMP), and service port or ICMP message type number. Individual acceptance, denial, and rejection rules are defined for the INPUT chain and the OUTPUT chain, as well as for the FORWARD chain, which you'll learn about at the end of this chapter and in Chapter 6, "Packet Forwarding." The next chapter pulls those ideas together to demonstrate how to build a simple, single-system, custom-designed firewall for your site.
Ubuntu's desktop install provides a bunch of useful software for desktop users, but it doesn't install a firewall by default. Luckily, it's really simple to get a firewall up and running on Ubuntu.
Frankly, I'm glad that the default install doesn't set up a firewall. Most of my computers live behind a firewall at all times anyway, and I've always been annoyed by installers that demand I deal with firewall questions when I've already got the situation well in hand. If I want a firewall on a machine, I can set one up on my own. Since Ubuntu is, in part, aimed at corporate desktops, a firewall is unnecessary for many installations.