DirectAccess

Last updated

DirectAccess, also known as Unified Remote Access, is a VPN technology that provides intranet connectivity to client computers when they are connected to the Internet. Unlike many traditional VPN connections, which must be initiated and terminated by explicit user action, DirectAccess connections are designed to connect automatically as soon as the computer connects to the Internet. DirectAccess was introduced in Windows Server 2008 R2, providing this service to Windows 7 and Windows 8 "Enterprise" edition clients. In 2010, Microsoft Forefront Unified Access Gateway (UAG) was released, which simplifies [1] the deployment of DirectAccess for Windows 2008 R2, and includes additional components that make it easier to integrate without the need to deploy IPv6 on the network, and with a dedicated user interface for the configuration and monitoring. Some requirements and limitations that were part of the design of DirectAccess with Windows Server 2008 R2 and UAG have been changed (see requirements below). While DirectAccess is based on Microsoft technology, third-party solutions exist for accessing internal UNIX and Linux servers through DirectAccess. With Windows Server 2012, DirectAccess is fully integrated into the operating system, providing a user interface to configure and native IPv6 and IPv4 support. [2]

Contents

Technology

DirectAccess establishes IPsec tunnels from the client to the DirectAccess server, and uses IPv6 to reach intranet resources or other DirectAccess clients. This technology encapsulates the IPv6 traffic over IPv4 to be able to reach the intranet over the Internet, which still (mostly) relies on IPv4 traffic. All traffic to the intranet is encrypted using IPsec and encapsulated in IPv4 packets (if a native IPv6 connection cannot be established), which means that in most cases, no configuration of firewalls or proxies should be required. [3] A DirectAccess client can use one of several tunneling technologies, depending on the configuration of the network the client is connected to. The client can use 6to4, Teredo tunneling, or IP-HTTPS, provided the server is configured correctly to be able to use them. For example, a client that is connected to the Internet directly will use 6to4, but if it is inside a NATed network, it will use Teredo instead. In addition, Windows Server 2012 provides two backward compatibility services DNS64 and NAT64, which allows DirectAccess clients to communicate with servers inside the corporate network even if those servers are only capable of IPv4 networking. Due to the globally routable nature of IPv6, computers on the corporate network can also initiate a connection to DirectAccess clients, which allows them to remotely manage (Manage Out) these clients at any time. [4]

Benefits

DirectAccess can be deployed for multiple sites. It allows for a secure encrypted VPN. This is controlled through Group Policies which allows the administrator to maintain a secure network.

Requirements

DirectAccess With Windows Server 2008 R2 or UAG requires:

DirectAccess With Windows Server 2012 requires:

Smart card certificates, and health certificates for Network Access Protection may be used along with PKI.

Related Research Articles

Active Directory (AD) is a directory service developed by Microsoft for Windows domain networks. It is included in most Windows Server operating systems as a set of processes and services. Initially, Active Directory was used only for centralized domain management. However, Active Directory eventually became an umbrella title for a broad range of directory-based identity-related services.

IPv6 Version 6 of the Internet Protocol

Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. IPv6 was developed by the Internet Engineering Task Force (IETF) to deal with the long-anticipated problem of IPv4 address exhaustion, and is intended to replace IPv4. In December 1998, IPv6 became a Draft Standard for the IETF, which subsequently ratified it as an Internet Standard on 14 July 2017.

Router (computing) Device that forwards data packets between computer networks

A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. Data sent through the internet, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork until it reaches its destination node.

Network address translation Protocol facilitating connection of one IP address space to another

Network address translation (NAT) is a method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device. The technique was originally used to avoid the need to assign a new address to every host when a network was moved, or when the upstream Internet service provider was replaced, but could not route the network's address space. It has become a popular and essential tool in conserving global address space in the face of IPv4 address exhaustion. One Internet-routable IP address of a NAT gateway can be used for an entire private network.

A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The benefits of a VPN include increases in functionality, security, and management of the private network. It provides access to resources that are inaccessible on the public network and is typically used for remote workers. Encryption is common, although not an inherent part of a VPN connection.

Zero-configuration networking (zeroconf) is a set of technologies that automatically creates a usable computer network based on the Internet Protocol Suite (TCP/IP) when computers or network peripherals are interconnected. It does not require manual operator intervention or special configuration servers. Without zeroconf, a network administrator must set up network services, such as Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS), or configure each computer's network settings manually.

In computer networking, Teredo is a transition technology that gives full IPv6 connectivity for IPv6-capable hosts that are on the IPv4 Internet but have no native connection to an IPv6 network. Unlike similar protocols such as 6to4, it can perform its function even from behind network address translation (NAT) devices such as home routers.

In computer networks, a tunneling protocol is a communication protocol which allows for the movement of data from one network to another, by exploiting encapsulation. It involves allowing private network communications to be sent across a public network through a process called encapsulation.

In computer networking, a host model is an option of designing the TCP/IP stack of a networking operating system like Microsoft Windows or Linux. When a unicast packet arrives at a host, IP must determine whether the packet is locally destined. If the IP stack is implemented with a weak host model, it accepts any locally destined packet regardless of the network interface on which the packet was received. If the IP stack is implemented with a strong host model, it only accepts locally destined packets if the destination IP address in the packet matches an IP address assigned to the network interface on which the packet was received.

Windows Firewall Firewall software for Windows

Windows Firewall, is a firewall component of Microsoft Windows. It was first included in Windows XP and Windows Server 2003. Prior to the release of Windows XP Service Pack 2 in 2004, it was known as Internet Connection Firewall. With the release of Windows 10 version 1709 in September 2017, it was renamed Windows Defender Firewall.

Network Access Protection (NAP) is a Microsoft technology for controlling network access of a computer, based on its health. With NAP, system administrators of an organization can define policies for system health requirements. Examples of system health requirements are whether the computer has the most recent operating system updates installed, whether the computer has the latest version of the anti-virus software signature, or whether the computer has a host-based firewall installed and enabled. Computers with a NAP client will have their health status evaluated upon establishing a network connection. NAP can restrict or deny network access to the computers that are not in compliance with the defined health requirements.

The domain name .local is a special-use domain name reserved by the Internet Engineering Task Force (IETF) so that it may not be installed as a top-level domain in the Domain Name System (DNS) of the Internet. As such it is similar to the other special domain names, such as .localhost. However, .local has since been designated for use in link-local networking, in applications of multicast DNS (mDNS) and zero-configuration networking (zeroconf) so that DNS service may be established without local installations of conventional DNS infrastructure on local area networks.

In computing, a shared resource, or network share, is a computer resource made available from one host to other hosts on a computer network. It is a device or piece of information on a computer that can be remotely accessed from another computer transparently as if it were a resource in the local machine. Network sharing is made possible by inter-process communication over the network.

Secure Socket Tunneling Protocol (SSTP) is a form of virtual private network (VPN) tunnel that provides a mechanism to transport PPP traffic through an SSL/TLS channel. SSL/TLS provides transport-level security with key negotiation, encryption and traffic integrity checking. The use of SSL/TLS over TCP port 443 allows SSTP to pass through virtually all firewalls and proxy servers except for authenticated web proxies.

Split tunneling is a computer networking concept which allows a user to access dissimilar security domains like a public network and a local area network or wide area network at the same time, using the same or different network connections. This connection state is usually facilitated through the simultaneous use of a LAN network interface controller (NIC), radio NIC, Wireless LAN (WLAN) NIC, and VPN client software application without the benefit of an access control.

In computing, Microsoft's Windows Vista and Windows Server 2008 introduced in 2007/2008 a new networking stack named Next Generation TCP/IP stack, to improve on the previous stack in several ways. The stack includes native implementation of IPv6, as well as a complete overhaul of IPv4. The new TCP/IP stack uses a new method to store configuration settings that enables more dynamic control and does not require a computer restart after a change in settings. The new stack, implemented as a dual-stack model, depends on a strong host-model and features an infrastructure to enable more modular components that one can dynamically insert and remove.

Microsoft Forefront Unified Access Gateway (UAG) is a discontinued software suite that provides secure remote access to corporate networks for remote employees and business partners. Its services include reverse proxy, virtual private network (VPN), DirectAccess and Remote Desktop Services. UAG was released in 2010, and is the successor for Microsoft Intelligent Application Gateway (IAG) which was released in 2007. UAG is part of the Microsoft Forefront offering. Microsoft discontinued the product in 2014, although the Web Application Proxy feature of Windows Server 2012 R2 and later offers some of its functionalities.

Routing and Remote Access Service (RRAS) is a Microsoft API and server software that makes it possible to create applications to administer the routing and remote access service capabilities of the operating system, to function as a network router. Developers can also use RRAS to implement routing protocols. The RRAS server functionality follows and builds upon the Remote Access Service (RAS) in Windows NT 4.0.

SoftEther VPN Open-source VPN client and server software

SoftEther VPN is free open-source, cross-platform, multi-protocol VPN client and VPN server software, developed as part of Daiyuu Nobori's master's thesis research at the University of Tsukuba. VPN protocols such as SSL VPN, L2TP/IPsec, OpenVPN, and Microsoft Secure Socket Tunneling Protocol are provided in a single VPN server. It was released using the GPLv2 license on January 4, 2014. The license was switched to Apache License 2.0 on January 21, 2019.

A DNS leak refers to a security flaw that allows DNS requests to be revealed to ISP DNS servers, despite the use of a VPN service to attempt to conceal them. Although primarily of concern to VPN users, it is also possible to prevent it for proxy and direct internet users.

References

  1. ↑ "Got DirectAccess? Get UAG!". Archived from the original on 2009-07-21. Retrieved 2017-03-23.
  2. ↑ "What's New in DirectAccess in Windows Server". technet.microsoft.com. Retrieved 2017-03-23.
  3. ↑ "DirectAccess: Microsoft's Newest VPN Solution - Part 1: Overview of Current Remote Access Solutions - TechGenix". www.windowsecurity.com. Retrieved 2017-03-23.
  4. ↑ "Configuring Manage Out to DirectAccess Clients | PACKT Books". www.packtpub.com. Retrieved 2017-03-23.
  5. ↑ "What's New in DirectAccess in Windows Server". technet.microsoft.com. Retrieved 2017-03-23.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.