1 Chapter 12: VPN Connectivity in Remote Access Designs Designs That Include VPN Remote Access Essential VPN Remote Access Design Concepts Data Protection in VPN Remote Access Designs VPN Remote Access Design Optimization

2 VPN Remote Access Solutions

3 Routing and Remote Access and VPN Virtual private network (VPN) gives control over Authorized user accounts Security methods Resources to be accessed Uses Point-to-Point Tunneling Protocol (PPTP) and Layer 2 Tunneling Protocol (L2TP) VPN and Remote Authentication Dial-In User Service (RADIUS) solutions differ in many ways.

4 Routing and Remote Access and Windows 2000 Routing and Remote Access in Microsoft Windows 2000 includes Remote access client Remote access server

5 VPN Clients and Servers

6 VPN Remote Access Design Review Amount of data transmitted Number of locations Existing Internet connections Plans for network growth Number of simultaneous clients Operating systems used by clients Protocols used by clients

7 VPN Remote Access Design Decisions Integration into existing network Hardware requirements for servers Protection for confidential data Availability to remote access users Optimization of network traffic

8 VPN Remote Access Designs A third party provides connectivity. Cost reduction is an advantage. Some dial-up security is not available. Caller ID detection Remote user callback Authentication protocol for dial-up connection Password security features

9 VPN Remote Access Scenario

10 Number of VPN Remote Access Servers Determine the maximum number of users. Determine the sustained data rate. Perform a pilot test. Calculate the number of servers.

11 Placing VPN Remote Access Servers Placement goals: Centralize administration Reduce costs Reduce network traffic Single location Multiple locations Adjacent to resources

12 Single Location Configuration Provide enough PPTP or L2TP virtual ports. Advantages Centralized administration Lower administration costs Disadvantages Increased network traffic on segments No redundancy

13 Multiple Location Configuration Provide enough PPTP or L2TP virtual ports. Advantages Reduced network traffic between locations Redundancy Disadvantages Decentralized administration and support Increased administration costs

14 Placing VPN Servers Near Resources Reduces the segments traversed Improves performance for remote access clients

15 Remote Access Client Support Virtual ports PPTP L2TP Transport protocols determined by client needs Network address assignment methods Allocate manually Allocate automatically using Dynamic Host Configuration Protocol (DHCP)

16 Preventing Unauthorized Access Restrict remote access to resources on the server. Use filters to restrict traffic on servers. Place VPN servers for security Outside the private network On screened subnets Within the private network

17 Placing VPN Servers Outside the Private Network

18 Placing VPN Servers on Screened Subnets

19 Placing VPN Servers Inside the Private Network

20 Protecting Remote Access Data Authenticate remote users. Local accounts Active Directory directory service accounts Encrypt confidential data. Microsoft Point-to-Point Encryption (MPPE) Internet Protocol Security (IPSec) Enforce remote access policies.

21 Enhancing Remote Access Availability Use redundant VPN remote access servers. Network Load Balancing Round robin DNS Use multiple Internet connections. Dedicate a computer to running Routing and Remote Access.

22 Improving Remote Access Performance Upgrade hardware. Distribute clients across multiple servers. Use Network Load Balancing. Use round robin DNS. Dedicate a computer to running Routing and Remote Access.

23 Chapter Summary There are many advantages in using VPN for remote access. Consider the number of users and the data rate. Use multiple remote access servers. Evaluate the needs of remote clients. Protect private network resources. Improve the availability and performance of the design.