Exam Highlights

Before taking the exam, review the key points and terms that are presented in this chapter. Return to the lessons for additional practice.

Key Points

• A firewall protects your network by blocking traffic through unwanted TCP ports and by filtering traffic through permitted ports. Exchange back-end servers require strong firewall protection. Exchange front-end servers can be in the DMZ, or perimeter network.

• You need to keep your operating systems, applications, antivirus software, and virus signature files up to date to protect against viruses, worms, and Trojan horses. Virus-clean policies need to be in place before a virus attack occurs.

• You can filter junk e-mail based on the address of a single sender, on a domain name, or on the recipient address (or lack of one). An RBL provides a third-party solution to the junk e-mail problem.

• Encryption ensures that only the person for whom a message is intended can read it, and a digital signature proves the sender's identity and gives an assurance that the message has not been altered in transit.

• You can delegate various levels of administrative control over an administrative group to users and to security groups.

• Disabling a service closes the port that the service uses so that it is not available to an attacker.

• You use Exchange System Manager to configure protocol logging for SMTP and NNTP virtual servers, and you use IIS Manager to configure protocol logging for HTTP virtual servers.

Key Terms

firewall A combination of hardware and software that provides a security system, usually to prevent unauthorized access to an intranet.

virus, worm, and Trojan horse Executable code that can damage data, applications, operating systems, and (sometimes) hardware. The difference between the three is in the method they use to spread through a network.

junk mail Unsolicited commercial e-mail, also known as spam e-mail.

administrative group A collection of Active Directory objects that are grouped together for the purpose of permissions management. An administrative group can contain policies, routing groups, public folder hierarchies, servers, and chat networks.

public key infrastructure (PKI) A system of digital certificates, certification authorities, and other registration authorities that verify and authenticate the validity of each party involved in an electronic transaction.