In many cases, each of these offices also have LANs. But how do the LANs connect? For some very specialized solutions, companies lease private lines to connect the offices. That can be very expensive. Instead, most companies opt to geographically connect separated private LANs over the public internet. To protect their data, they set up VPNs between offices, encrypting the data as it traverses the public internet.

There’s no point to a VPN that interferes with or logs your traffic—your ISP already does that. Free VPNs, such as Facebook’s Onavo, explicitly gather traffic data to resell or use it for marketing. We looked carefully at the privacy policies and marketing claims for each company we considered. In some cases, companies we considered had sworn in court filings that requests for data were impossible to fulfill. In other cases, we asked companies about their internal security and privacy standards to gauge the trustworthiness of their statements on logging.
VPNs secure your traffic and route it through an intermediary server so it can’t be traced. But if privacy is not of chief concern to you, then there are other alternative proxy methods that offer faster speed. A SOCKS proxy, for example, does pretty much the same thing as a VPN without the encryption. Without having to encrypt and decrypt traffic, SOCKS proxy users can get faster speeds and still mask their IP address.
In this approach, the firewall must be configured with input and output filters on its Internet and perimeter network interfaces to allow the passing of tunnel maintenance traffic and tunneled data to the VPN server. Additional filters can allow the passing of traffic to Web servers, FTP servers, and other types of servers on the perimeter network. As an added layer of security, the VPN server should also be configured with PPTP or L2TP/IPSec packet filters on its perimeter network interface as described in “VPN Server in Front of a Firewall” in this section.

For two years running, Private Internet Access has performed the best in our network tests and remained the cheapest full-fledged VPN service we've tried. It has more than 3,000 servers worldwide, supports platforms ranging from Windows and Mac to open-source routers, and lets you customize your tunneling and encryption protocols. You can pay in bitcoin, and you don't have to provide your real name.
Auto-static refers to the automatic adding of the requested routes as static routes in the routing table. The sending of the request for routes is performed through an explicit action, either through Routing and Remote Access or the Netsh utility while the demand-dial interface is in a connected state. Auto-static updates are not automatically performed every time a demand-dial connection is made.
SSTP, Secure Socket Tunneling Protocol is designed to work on Windows only. It is considered as a fast secure VPN protocol as it supports up to 256-bit encryption to route the traffic. SSTP uses SSL channels to pass all PPTP and L2TP protocol that makes the browsing journey secure and fast. It is also designed in a way to bypass intense geo-restriction and break the firewalls. The only demerit we see in SSTP fast VPN protocol is its limited support on OS and devices. Although, if you compare PPTP and L2TP parallel to SSTP, you will not experience a high-speed VPN connection, it is to understand that SSTP is more focused on delivery privacy coupled with adequate speed.
IPSec NAT-T enables IPSec peers to negotiate and communicate when they are behind a NAT. To use IPSec NAT-T, both the remote access VPN client and the remote access VPN server must support IPSec NAT-T. IPSec NAT-T is supported by the Windows Server 2003 Microsoft L2TP/IPSec VPN Client and by the L2TP/IPSec NAT-T Update for Windows XP and the L2TP/IPSec NAT-T Update for Windows 2000. During the IPSec negotiation process, IPSec NAT-T-capable peers automatically determine whether both the initiating IPSec peer (typically a client computer) and responding IPSec peer (typically a server) can perform IPSec NAT-T. In addition, IPSec NAT-T-capable peers automatically determine if there are any NATs in the path between them. If both of these conditions are true, the peers automatically use IPSec NAT-T to send IPSec-protected traffic.
Initially, the routing table for each router includes only the networks that are physically connected. A RIP router periodically sends announcements that contain its routing table entries to inform other local RIP routers of the networks it can reach. RIP version 1 uses IP broadcast packets for its announcements. RIP version 2 can use multicast or broadcast packets for its announcements.
Remote-access VPNs come in two forms. One is a network access server (NAS), which is a dedicated server, or an application running on a shared server. In this case, users need to connect to the NAS over the Internet to access the VPN. Users key in their credentials to access the VPN, which is validated by the NAS either by using a separate authentication server or its own authentication process.
Then there’s the widespread surveillance by local and foreign governments. Through the Snowden leaks and years of follow-up reporting, we know that the worldwide surveillance structure is vast in scope and reach. While it would be illegal for police officers to search your home without a warrant, your browsing activity, messages, social media content, and other online information can be monitored, retained and shared among various government agencies, including across country borders.

In short, it's time to start thinking about protecting your personal information. That's where virtual private networks, or VPNs, come in. These services use simple software to protect your internet connection, and they give you greater control over how you appear online, too. While you might never have heard of VPN services, they are valuable tools that you should understand and use. So who needs a VPN? The short answer is that everyone does. Even Mac users can benefit from a VPN.