Prototypes based on OpenvSwitches (OVS) have been implemented for experimentation across the PEERING BGP testbed. The solution works with both IPv4 and IPv6, whereas the latter provides higher degrees of IP addressing freedom. We demonstrate how this is doable today with three different strategies using software defined networking (SDN), and how this can be done at scale to transform the Internet addressing and routing paradigms with the novel concept of a distributed software defined Internet exchange (SDX). The concept is seemingly impossible to realize in todays Internet. In this work, we explore an alternative network architecture that fundamentally removes such vulnerabilities by disassociating the relationship between IP prefixes and destination networks, and by allowing any end-to-end communication session to have dynamic, short-lived, and pseudo-random IP addresses drawn from a range of IP prefixes rather than one. As a result, network communications can be easily identified using IP addresses and become targets of a wide variety of attacks, such as DNS/IP filtering, distributed Denial-of-Service (DDoS) attacks, man-in-the-middle (MITM) attacks, etc. Internet autonomous systems (AS) possess fixed IP prefixes, while packets carry the intended destination AS's prefix in their headers, in clear text. Finally, we performed a University closed survey in order to find out circumvention techniques adopted by users in Pakistan and we report that Pakistani users try to evade censorship by using web proxies, Tor and VPN.ĭestination IP prefix-based routing protocols are core to Internet routing today. We comment on these results by considering the evolution over time of the forced censorship mechanisms. Our results show that (i) WiTribe, PTCL, and Nayatel block content by using DNS tampering while (ii) Wateen and Qubee apply filtering, using HTTP tampering. This is the first study in literature analyzing and comparing the behaviour of five ISPs in Pakistan using automated detection methods based on active probing measurements. This paper presents the methodology and the measurement analysis based on publicly available censored URLs in Pakistan, providing both qualitative and quantitative results to gauge how major ISPs are censoring web content in Pakistan. According to latest Open Net Initiative (ONI) report, almost 50 countries are involved in web censorship, including Pakistan. Internet Censorship is unceasingly increasing in many countries worldwide in order to restrict web contents within the country premises. Responses from developers of the tools in question are included in the report. Many of the findings of the report are now out of date, but we present them now, as is, because we think that the broad conclusions of the report about these tools remain valid and because we hope that other researchers will benefit from access to the methods used to test the tools. The report was completed in 2007 and released to a group of private sponsors. We find that, in general, the tools work in the sense that they allow users to access pages that are otherwise blocked by filtering countries but that performance of the tools is generally poor and that many tools have significant, unreported security vulnerabilities. Some tools use proxies that are centrally hosted, others use proxies that are peer hosted, and others use re-routing methods that use a combination of the two. ![]() We find that all of the tools use the same basic mechanisms of proxying and encryption but that they differ in their models of hosting proxies. We evaluated these tools in 2007 - using both tests from within filtered countries and tests within a lab environment - for their utility, usability, security, promotion, sustainability, and openness. ![]() In this report, we describe the mechanisms of filtering and circumvention and evaluate ten projects that develop tools that can be used to circumvent filtering: Anonymizer, Ultrareach, DynaWeb Freegate, Circumventor/CGIProxy, Psiphon, Tor, JAP, Coral, and Hamachi. A large variety of different projects have developed tools that can be used to circumvent this filtering, allowing people in filtered countries access to otherwise filtered content. ![]() As the Internet has exploded over the past fifteen years, recently reaching over a billion users, dozens of national governments from China to Saudi Arabia have tried to control the network by filtering out content objectionable to the countries for any of a number of reasons.
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