Exam Objectives Frequently Asked Questions

The following Frequently Asked Questions, answered by the authors of this book, are designed to both measure your understanding of the Exam Objectives presented in this chapter, and to assist you with real-life implementation of these concepts. You will also  gain access to thousands of  other  FAQs at ITFAQnet.com.

1.	Are VPN connections more secure than regular dial-up connections?
2.	Do vendors besides Microsoft support RIP and OSPF?
3.	Do demand dial routes use OSPF?
4.	Can L2TP be used if my network uses Network Address Translation (NAT)?
5.	If L2TP is more secure than PPTP, why would I want to use PPTP at all?
6.	Can my VPN be used behind a firewall?

Answers

1.	No. Regular dial-up connections do not transfer data over public networks. The capability of most attackers to intercept packets crossing the analog telephone network is small at best. With proper design, however, VPN connections can be made very secure.
2.	Yes, but support for OSPF is more ubiquitous. OSPF is more complex than RIP, but is more efficient. Both protocols can be secured.
3.	No. Static routes must be manually added for use with demand dial routes. Automatic static routes can be used, with slightly increased security risk.
4.	Windows Server 2003 supports NAT Traversal (NAT-T), which means that L2TP packets can be forwarded across NAT. PPTP can cross a NAT server without the aid of NAT-T.
5.	Using L2TP requires an existing public key infrastructure (PKI) in order to support certificate authentication. Implementing such an infrastructure can be needlessly complicated in a smaller network or one that does not require the highest security levels.
6.	Yes, but you will need to let through the appropriate tunneling traffic. This can mean allowing TCP port 1723 for PPTP, UDP port 500 and UDP Port 1701 among others for L2TP. If a firewall blocks everything but what is absolutely necessary, it is doing its job.