Linux Firewall - Page 11
We have thousands of posts on a wide variety of open source and security topics, conveniently organized for searching or just browsing.
We have thousands of posts on a wide variety of open source and security topics, conveniently organized for searching or just browsing.
bit_of_love sent us a note about an interview with Harald Welte. "UnderLinux has an interesting interview with Harald Welte, member of netfilter/iptables project core team. Harald told about his carrer, dificulties in iptables project, Brazil and Free software, GNU/HURD and, of course, the new iptables2 to kernels 2.5.x/2.6.x.". . .
Mike Murray describes how he patched the 2.2 Linux kernel to run an ipchains packet filtering firewall when the machine is halted. "As systems administrators, it's often funny how new and interesting information ends up in our hands. Sometimes, it's through an intentional course of study; other times, it seems to arrive by accident. That's exactly how the concept of using a halted Linux computer as a firewall occurred to me. . . .
In Part I of this two-part series on the Linux Packet Filter, Gianluca describes a packet's journey through the kernel. Network geeks among you may remember my article, ``Linux Socket Filter: Sniffing Bytes over the Network'', in the June 2001 issue of LJ, regarding the use of the packet filter built inside the Linux kernel.. . .
A firewall is software that prevents the flow of Internet traffic. Businesses and large network administrators use firewalls to contain traffic and maintain security. Firewalls keep traffic out, or they keep it in. A simple firewall configuration for most home users would block all outside traffic not generated at the users' request.. . .
The 2.4 Kernel of Linux has a great tool called netfilter, which is a framework for creating firewalls. Many new Linux distributions such as RedHat 7.1 come with basic firewall rulesets that allow you to automatically create low, medium, or high . . .
There's a nice recipe for making a tasty, high-performance security checkpoint to replace a bland, low-performing single point of failure at the border between your network and the Internet.
This article dated back in 1998 is one of the most informative articles I've seen on Application Gateways and Stateful Inspection. The Internet Security industry has grown tremendously in the past several years: the increase in demand for related products has . . .
PCX Firewall is a perl script which works with several configuration files to generate 3 shell scripts (startfw, stopfw, and restartfw) which actually do the real work of the firewall. The design goal was to develop a complete IPTables based . . .
The IPTables/NetFilter application is considered to be the fourth generation of Linux packet filtering implementations. The first generation was Alan Cox's port of BSD UNIX's ipfw to Linux 1.1. Jos Vos and others extended this and added the ipfwadm user tool . . .
In a bid to fight the growing menace from computer and router-based denial of service (DoS) attacks, security firm have developed a technique to dam the DoS data flood at source. Using funding from the Defence Advanced Research Projects Agency . . .
There's no question that firewalls are a key weapon in the IT arsenal. From a business perspective, the case for purchasing the right firewall for the job at hand is simple: Downtime costs money. Lost data costs money. A hacked site . . .
A draft of the Guide to Firewall Selection and Policy Recommendations (.pdf format) is now available for public comment. This document is intended for technical managers in the firewall and network security areas, but it would also prove useful to those wishing to know more about firewall technology and recommended policies. . . .
Transparent proxying frees you from the hassle of setting up individual browsers to work with proxies. If you have a hundred, or a thousand, users on your network, it's a pain to set up each browser and to use proxies -- or to try to convince users to go into their preferences and type in these symbols they don't understand.. . .
With the numbers of hackers and viruses these days, everyone who has a computer that's connected to a network -- including the Internet -- should have a firewall or be running behind one. This is a Q&A sessions about firewalls with . . .
... the latest Linux kernel, version 2.4, offers a number of improvements over the 2.2 kernel that make Linux a viable alternative for corporate firewalls. Netfilter, Linux's in-kernel "packet mangling" infrastructure, and iptables, the administrative tool that manages it, represent a . . .
The 2.2 version of the Linux kernel used the ipchains application to control the firewall. For standard firewalling, ipchains is a decent solution. We still use it on some of our machines, and there is still a positive argument for 2.2 . . .
The FTP protocol has strange peculiarities that make working behind a firewall somewhat difficult if not quite impossible. This document explains the problem, and solutions for both client and server behind a gateway doing NAT. AFAIK, it's the first time a solution is proposed for the server. Details of this solution are given for OpenBSD.. . .
For those of you who have taken the plunge and upgraded from kernel 2.2.X (or even 2.0.X) to 2.4.X, congratulations. If, like a number of folks, you're running some form of firewall using either ipchains or ipfwadm, your scripts may work . . .
What is IPFilter? Very simply, a package for permitting (or passing) and denying IP packets based on a range of criteria. It can also provide Network Address Translation (NAT) services, if desired. The IPFilter web site has more details. . . .
Firewalls are the bestsellers of tech security, cheap, formulaic and popular. Like a good paperback, they offer a pleasant escape from reality. An entire generation of business executives has come of age trained on the notion that firewalls are the . . .