Doug Vitale Tech Blog

Posts Tagged ‘online

Tor anonymity: how it works and how to use it

The Onion Router (TOR) network is intended to help protect the privacy of Internet users and promote greater freedom of expression online. Tor is a system of volunteer servers that acts as a buffer between Internet users and the resources they connect to. If you connect as a Tor client, your online access is channeled through this buffer before it reaches the general Internet. To understand clearly how Tor functions, you must first have a good idea of what proxy servers are, and of the role they play during network transmissions.

A proxy server acts as a middleman between a client computer and the target server or resource it is accessing. As such, proxies can be configured to log user activity and restrict Internet access; for example, by blocking certain websites or protocols. However, proxies can also help protect the client user’s privacy because the target server is only aware that it is communicating with the proxy, not with the client. For example, if you connect to a web proxy and then load a website, the site is only aware that it is being accessed by the proxy and it has no knowledge of your computer and IP address. The illustration below depicts network data flow when a proxy is deployed. Resources within the Internet icon (such as web servers) are only aware of the proxy server, not of the three clients behind it.

Internet access through a proxy server

The “Internet” only knows about the proxy, not the three clients

Now what if instead of using a single proxy server, you could connect to a network of them for increased bandwidth and availability? And what if you could encrypt your communication sessions for increased confidentiality? Using Tor, you can.

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Written by Doug Vitale

May 29, 2012 at 11:06 PM

Troubleshooting faulty network connectivity, part 1: A step-by-step guide

(Go to Part 2 of this series).

“My computer won’t connect to the Internet”.

“I can’t get online; Windows says it only has limited network connectivity”.

“I’m getting ‘page cannot be displayed’ errors”.

“I can’t find the file server”.

If you have worked as a network administrator or help desk specialist, you have probably heard these complaints and variants of them more times than you can count. Between improper IP addressing, malfunctioning hardware or faulty cables, incorrect DNS resolution, incorrect access permissions and a slew of other factors, there are many reasons why modern computer users could experience difficulty getting their client machines online and/or connecting to the resources that they need (i.e., the Internet in general, a certain website, a network share, a printer, etc).

Difficulties can range from the inability to get an IP address from a DHCP server, incorrect DNS server IP addresses on the client, malfunctioning DNS servers, a faulty network interface card (NIC) or NIC driver, malware attacks, strict firewall rules, misconfigured Web browsers, etc.

Given the many interconnected technologies that work together to provide modern computer networking, it is no surprise that the inability to get online is one of the most common complaints of computer users. An inspection of any Web discussion forum focusing on technical support will reveal that networking problems are among the most common challenges that users face (see, for example, Computer Hope and Tech Support Guy).

Since so many networking component technologies could be the culprits behind a lack of connectivity, a unified methodology towards troubleshooting network errors and outages is ideal for technicians. Why? To help ensure that you do not overlook any steps, or do any unnecessary or repetitive work as you attempt to establish the required connectivity.
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