User's Manual
Table Of Contents
- Reference Manual for the NETGEAR ProSafe VPN Client
- Contents
- Chapter 1 About This Manual
- Chapter 2 Introduction
- Chapter 3 Installation
- Chapter 4 Configuring L2TP Connections
- Chapter 5 Using the Security Policy Editor
- What is the Security Policy Editor?
- Basic Steps to Configure a Security Policy
- How to Secure All Connections
- How to Configure Global Policy Settings
- How to Configure Other Connections
- How to Add and Configure a Connection
- How to Enter a Preshared Key
- How to Configure a Gateway
- Configure My Identity
- Configure Security Policy Connection Options
- Configure Authentication (Phase 1)
- Configure Key Exchange (Phase 2)
- Edit a Distinguished Name
- Configure and Manage Connections
- Manage Proposals
- Manage Redundant Gateways
- Manage the Security Policy
- Chapter 6 Using the Certificate Manager
- What is the Certificate Manager?
- Obtain Certificates
- With Online (SCEP) Enrollment
- CAs that Support SCEP
- Retrieve a CA Certificate Online
- Configure a CA Certificate
- Use an HTTP Proxy Server for Online Certificate Requests and CRL Updates
- Import a CA Certificate
- Select a CSP
- Request a Personal Certificate
- Define How Often to Check for and Retrieve New Personal Certificates
- Retrieve a Personal Certificate Manually
- Manage Certificate Requests
- With Manual (File-Based) Enrollment
- Obtain Certificates Through Internet Explorer
- With Online (SCEP) Enrollment
- Manage Certificates
- Manage Certificate Revocation Lists (CRLs)
- Manage the Trust Policy
- Chapter 7 Using Sessions
- Chapter 8 Distributing Customized Profiles
- Chapter 9 Troubleshooting
- Appendix A Networks, Routing, and Firewall Basics
- Appendix B Virtual Private Networking
- Appendix C NETGEAR ProSafe VPN Client to NETGEAR FVS318 or FVM318 VPN Routers
- Appendix D NETGEAR VPN Client to NETGEAR FVL328 or FWAG114 VPN Router
- Glossary
- Index
Reference Manual for the NETGEAR ProSafe VPN Client
A-8 Networks, Routing, and Firewall Basics
202-10015-01
Single IP Address Operation Using NAT
In the past, if multiple PCs on a LAN needed to access the Internet simultaneously, you had to
obtain a range of IP addresses from the ISP. This type of Internet account is more costly than a
single-address account typically used by a single user with a modem, rather than a router. The
NETGEAR VPN Client employs an address-sharing method called Network Address Translation
(NAT). This method allows several networked PCs to share an Internet account using only a single
IP address, which may be statically or dynamically assigned by your ISP.
The router accomplishes this address sharing by translating the internal LAN IP addresses to a
single address that is globally unique on the Internet. The internal LAN IP addresses can be either
private addresses or registered addresses. For more information about IP address translation, refer
to RFC 1631, The IP Network Address Translator (NAT).
The following figure illustrates a single IP address operation.
Figure A-3: Single IP Address Operation Using NAT
This scheme offers the additional benefit of firewall-like protection because the internal LAN
addresses are not available to the Internet through the translated connection. All incoming
inquiries are filtered out by the router. This filtering can prevent intruders from probing your
system. However, using port forwarding, you can allow one PC (for example, a Web server) on
your local network to be accessible to outside users.
1
92.168.0.2
1
92.168.0.3
1
92.168.0.4
1
92.168.0.5
192.168.0.1 172.21.15.105
Private IP addresses
assigned by user
Internet
IP addresses
assigned by ISP