Overly broad permissions can turn one compromised account into a much larger security problem. Learn how to reduce unnecessary access, review privileges, and apply least privilege across modern Linux systems. Review Linux Privileges×
You manage a heterogeneous network and want to provide different Quality of Service agreements and network restrictions based on the client operating system. With pf and altq, you can now limit the amount of bandwidth available to users of different operating systems, or force outbound web traffic through a transparent filtering proxy. This article describes how to install pf, altq, and Squid on your FreeBSD router and web proxy to achieve these goals. . In an ideal environment, there would be no need for bandwidth shaping, OS fingerprint-based filtering, or even Quality of Service (QoS). Several factors in the real world require a change of game plan. Bandwidth is not free, and many ISPs charge customers based on bandwidth usage. Worms, viruses, and compromised systems can all lead to higher bandwidth costs. In the wake of the W32.Slammer worm, which saturated the connections of infected networks, many companies saw their monthly connectivity bills skyrocket due to the worm's traffic. Filtering your connections based on operating system can go partway to helping keep such situations from running away. While I will focus on filtering traffic from Windows systems, this process can equally apply to BSD, Linux, Mac OS, or a host of other operating systems listed in the pf.os file on your system. This may be especially useful to people running older versions of OSes that have not or cannot be patched but still require some network connectivity. . In an ideal environment, there would be no need for bandwidth shaping, OS fingerprint-based filterin. manage, heterogeneous, network, provide, different, quality, service, agreements. . Brittany Day
Routers and switches are the keys to a strong network foundation. Together they enable the intelligent, end-to-end movement of converged data, voice, and video information within or outside the business. . . .. A solid network foundation is the key to business agility, process efficiency, productivity, and competitiveness. It provides intelligent services such as security, availability, reliability, and quality of service (QoS). This makes it possible for small-medium companies to run desired business applications and advanced technologies, establish competitive advantage, extend or streamline their operations, improve responsiveness to customers and partners, and reduce the costs of ongoing network management. Routers and switches are the keys to a strong network foundation. Together they enable the intelligent, end-to-end movement of converged data, voice, and video information within or outside the business. The link for this article located at InformIT is no longer available. . A robust connectivity backbone is essential for enhanced flexibility, productivity, and market edge in today’s corporate landscapes.. Network Security, Routers, Switches, Business Agility, Quality of Service. . Anthony Pell
On Thursday, February 20, 2003, at about 0130 GMT, the popular LiveJournal site became the victim of a massive distributed denial-of-service attack. LiveJournal staffers and upstream providers first tried to filter by IP, but they soon discovered what the "D" in . . . . On Thursday, February 20, 2003, at about 0130 GMT, the popular LiveJournal site became the victim of a massive distributed denial-of-service attack. LiveJournal staffers and upstream providers first tried to filter by IP, but they soon discovered what the "D" in DDOS means. After blocking about one quarter of the IP addresses on the Internet, they got on their load balancer and implemented some unknown but effective measures (repeated e-mails to them went unanswered). I can only assume these measures included some quality of service/rate limiting methods. Despite continued flooding, the site returned to usability after about four days of being somewhere between slow and totally unreachable. Being a paid LiveJournal subscriber myself, I roused myself from the storm of dark imprecations on the soul of someone who would try to destroy a site that has become the epitome of "on-line community" to wonder, what do you do about such an event? The link for this article located at LinuxJournal is no longer available. . DDoS (Distributed Denial of Service) attacks pose serious risks to network stability and access. Here are key strategies to prevent and recover from them. DDoS Prevention, Network Attack Techniques, Traffic Management Solutions. . Anthony Pell
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