Understand Network Isolation Part 2 LESSON 3.3_B Security Fundamentals

LESSON 3.3_B Lesson Overview In this lesson, you will learn about:  VPN  Perimeter network  Honeypot  Server and domain isolation

Security Fundamentals LESSON 3.3_B Anticipatory Set Many risks are associated with VPNs because workstations connect to the network and measures need to be addressed to ensure that the risk is eliminated. 1. What are these risks? 2. How can you control access?

Security Fundamentals LESSON 3.3_B VPN and Perimeter Network  In a common configuration the firewall is connected to the Internet and the VPN server is another intranet resource connected to a perimeter network. o The perimeter network is an IP network segment that typically contains resources available to Internet users such as Web servers and FTP servers. o The VPN server has an interface on the perimeter network and an interface on the intranet.  The firewall must be configured with input and output filters on its Internet interface to allow the passing of tunnel maintenance traffic and tunneled data to the VPN server.  Additional filters can allow the passing of traffic to Web servers, FTP servers, and other types of servers on the perimeter network.

Security Fundamentals LESSON 3.3_B VPN and Perimeter Network (continued)

Security Fundamentals LESSON 3.3_B VPN  A virtual private network.  The extension of a private network that encompasses links across shared or public networks like the Internet.  Enables you to send data between two computers across a shared or public internetwork in a manner that emulates the properties of a point- to-point private link.  Configuring and creating a virtual private network is known as virtual private networking.

Security Fundamentals LESSON 3.3_B VPN (continued)

Security Fundamentals LESSON 3.3_B Basic VPN Scenario  Used to facilitate controlled access to organization resources and information.  Must allow roaming or remote clients to connect to LAN resources.  Must allow remote offices to connect to each other to share resources and information (router-to-router connections).  Must ensure the privacy and integrity of data.  Helps reduce the risk of network-borne security threats.  Therefore, a VPN solution should provide at least all of the following:  User Authentication  Address Management  Data Encryption  Key Management

Security Fundamentals LESSON 3.3_B Basic VPN Elements Honeypots  Performs a function very similar to that of a “honeypot” in the outside world: a sweet lure.  Used to attract the attention of prospective attackers, to learn how they are attempting to infiltrate the system and what they would likely do once they gain access.  There are literally thousands of honeypot networks and systems available from security professionals and hobbyists. o Can provide a wealth of information in assessing trends in network intrusion.

Security Fundamentals LESSON 3.3_B Basic VPN Elements (continued) Server and Domain Isolation  A solution based on Microsoft ® Windows ® Internet Protocol security (IPsec) and the Active Directory ® Domain Services enables administrators to dynamically segment their Windows environment into more secure and isolated logical networks based on policy and without costly changes to their network infrastructure or applications.  Benefits: o Creates an additional layer of protection. o Helps better protect against costly network attacks. o Helps prevent unauthorized access to trusted networked resources. o Achieves regulatory compliance. o Reduces operational costs.

Security Fundamentals LESSON 3.3_B Server and Domain Isolation

Security Fundamentals LESSON 3.3_B Lesson Review A few useful tools for Intrusion Detection and Integrity Analysis are:  Tripwire: (sourceforge.net/projects/tripwire/) For monitoring data integrity. It takes a snapshot of a system binaries (or other directory), creates a checksum, checks system integrity, and reports any deviation.  The Coroner's Toolkit: ( A suite of utilities for checking running process and file/filesystem information, recent changes, and other such information.  Snort: ( A great tool for traffic analysis and intrusion detection. There is a great FAQ on the website.  Chkrootkit: (freshmeat.net) A utility for identifying rootkits installed on the system.