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Server Connectivity
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RAS (Remote Administration Service)

Overview

    RAS is the NT service that allows dial-up network connections between a RAS server and a dial-up client. RAS is very complex I don't know many administrators including myself who understand this completely. I recommend that you study very well for this area of the NT tests.

    RAS can be implemented on NT Servers and NT Workstations, with the main difference between the two is that Server can support 256 simultaneous connections while Workstation can only support one. Different types of operating systems can be configured as dial-up networking clients and connect to a RAS server, including: MSDOS, Windows 3.1x, Windows 9x, and Windows NT.

Connection Types

    Dial-up clients can use several different methods to connect to a RAS Server, including:

  1. An analog phone line and a modem- probably the most common type of connection.
  2. ISDN (Integrated Services Digital Network) - Is a digital phone connection capable of transferring data at 128KBps. ISDN is growing in popularity as the service is becoming offered to a wider audience.
  3. X.25 - Is a packet switching protocol that is used over dial-up or leased lines. You must have a X.25 adapter card and a PAD(packet assembler / dissembler to use this. Not very popular.
  4. PPTP (Point to Point Tunneling Protocol) is used when you want to establish a VPN (Virtual Private Network) over the internet.

Connection Protocols Supported by RAS

  1. SLIP (Serial Line Internet Protocol) - This is an older protocol usually used with UNIX machines. It can only support one transport protocol TCP/IP. Therefore it can not be used with NetBEUI or NWLink. It does not support password encryption.
  2. PPP (Point to Point Protocol) - This is the most common connection protocol. It is currently the industry standard in connection protocols. It can connect multiple transport protocols TCP/IP, NWLink, and NETBEUI. It supports password encryption and dynamic IP addressing.

Transport Protocols Supported by RAS

  1.    NetBEUI
  2.     TCP/IP
  3.     NWLink

    DLC Protocol is not supported by RAS

RAS Name Resolution - The same methods employed by other network function are used to resolve netbios names while using RAS.

  1. NetBios Broadcasts
  2. WINS Servers
  3. DNS
  4. LMHOSTS
  5. HOSTS

Installing RAS

   RAS is a network service and is installed using the network applet in Control Panel. After you start the installation and all the files are copied you must set up the modems or other connection devices to use RAS. A wizard steps you through the process so I suggest you give it a try yourself.

Remote Access Admin

   Remote Access Admin is the administration tool you use to manage the RAS Server. You can use it to assign dial in permission and  configure call back security for users. You can also use it to view connections to ports or to disconnect users from the service. Remote Access Admin is automatically installed when you install RAS.

RAS Security

    RAS can be set up to accept several different security settings

  1. Accept any authentication including clear text - This is the choice you would want to make if you have several different types of OS's connecting to the RAS server. The passwords sent to the server will not be encrypted in any way.
  2. Accept only encrypted authentication - To use this all clients must support some type of password encryption.
  3. Accept only Microsoft Encryption authentication - You must use this if you want to require data encryption. There are two different options for this authentication.

                Require Data Encryption- Check this box if you want to                   encrypt all data sent between the computers.

                Use Current Username and Password - If you select this then                   RAS will not prompt for the user to log into the RAS                   machine but will use the current user name and password.

RAS is a broad subject and I will be adding more to this page as I get time. A good book I found is Windows Remote Access Toolkit. This is a excellent book to read if you're interested in learning more about this fascinating subject.