1 Configuring Virtual Private Networks for Remote Clients and Networks

2 What Is Virtual Private Networking? Virtual private networking allows secure remote access to resources on an organization’s internal network for users outside the network A VPN is a virtual network that enables communication between a remote access client and computers on the internal network or between two remote sites separated by a public network such as the Internet

3 Types of VPNs Remote Access VPN – Provides access to internal corporate network over the Internet – Reduces long distance, modem bank, and technical support costs Internet Corporate Site

4 Types of VPN Site-to-Site VPN – Connects multiple offices over Internet – Reduces dependencies on frame relay and leased lines Internet Branch Office Corporate Site

5 Types of VPN Extranet VPN – Provides business partners access to critical information (leads, sales tools, etc) – Reduces transaction and operational costs Corporate Site Internet Partner #1 Partner #2

6 What a VPN needs VPNs must be encrypted – so no one can read it VPNs must be authenticated No one outside the VPN can alter the VPN All parties to the VPN must agree on the security properties

7 VPN Topology Operates at layer 2 or 3 of OSI model – Layer 2 frame – Ethernet – Layer 3 packet – IP Tunneling – allows senders to encapsulate their data in IP packets that hide the routing and switching infrastructure of the Internet – to ensure data security against unwanted viewers, or hackers

8 VPN Components Protocols: IP Security (IPSec) – Transport mode – Tunnel mode Point-to-Point Tunneling Protocol (PPTP) – Voluntary tunneling method – Uses PPP (Point-to-Point Protocol)

9 VPN Components Protocols: Layer 2 Tunneling Protocol (L2TP) – Exists at the data link layer of OSI – Composed from PPTP and L2F (Layer 2 Forwarding) – Compulsory tunneling method

10 VPN Components Security: Authentication – Determine if the sender is the authorized person and if the data has been redirect or corrupted – User/System Authentication – Data Authentication

11 VPN Components

12 Configuring Virtual Private Networking for Remote Clients

13 Creating a Remote Access PPTP VPN Server Enabling the ISA Firewall’s VPN Server component Creating an Access Rule allowing VPN Clients access to the Internal network Enabling Dial-in Access for VPN User Accounts Testing a PPTP VPN Connection

14 Enable the VPN Server Enable VPN Client Access Warning About address assignment

15 Assigning IP Address Assignment for Remote Users Remote users that will be establishing a VPN tunnel require an IP address to properly communicate through the tunnel to the internal network

16 Authenticating VPN Users Authenticating directly against Active Directory Implement RADIUS Authentication Authenticate against local users

17 Working with and Creating Rules for the VPN Clients Network create default rules that allow VPN clients access into the network create default rules that allow VPN clients access into the network

18 RADIUS Authentication for VPN Connections Install the Internet Authentication Service (IAS) for Active Directory RADIUS Support

19 Setting Up the ISA Server as an IAS Client Define a RADIUS server shared key

20 Configuring ISA to Use IAS for Authentication Define a RADIUS server shared key in ISA Modify RADIUS server settings for VPN client access

21 Configuring an ISA VPN Connection to Use PPTP

22 Creating Layer 2 Tunneling Protocol (L2TP) VPN Enter an IPSec pre-shared key.

23 Creating a Public Key Infrastructure (PKI) for L2TP with IPSec Support Installing the Enterprise Root Certificate Authority (CA) Configuring the Enterprise Root CA Requesting a Certificate for the ISA VPN Server Requesting a Certificate for the VPN Client Downloading the CA Certificate Exporting and Importing Certificates

24 Configuring Virtual Private Networking for Remote Sites

25 Site-to-Site VPN Capabilities Point-to-Point Tunneling Protocol (PPTP) Layer 2 Tunneling Protocol (L2TP) IPSec Tunnel Mode

26 Preparing ISA Servers for Site-to-Site VPN Capabilities Define the IP Address Assignment Enable VPN client access Create local VPN user accounts on both servers, and enable dial-in access for those accounts. Run through the Site-to-Site VPN wizard to configure all necessary networks, network rules, and access rules. Repeat the steps on the remote server.

27 Create VPN Site-to-Site

28 Configuring a Point-to-Point Tunneling Protocol (PPTP) Site-to-Site VPN Between Two Remote Offices Create a PPTP Site-to-Site VPN Connection

29 Configuring a Layer 2 Tunneling Protocol (L2TP) Site-to-Site VPN Deciding Between Shared Key and PKI Configuring a PKI Infrastructure for PKI-Based Certificate Encryption Requesting a Certificate for the ISA VPN Server Creating an L2TP/IPSec Site-to-Site VPN Connection

30 Setting Up an IPSec Tunnel Mode VPN Connection