Home > Articles > CCNA Security: Defending the Perimeter

CCNA Security: Defending the Perimeter

  • Sample Chapter is provided courtesy of Cisco Press.
  • Date: Jun 30, 2008.


  1. "Do I Know This Already?" Quiz
  2. Foundation Topics
  3. Exam Preparation Tasks

Chapter Description

This chapter covers an ISR overview and how to provide secure administrative access and a Cisco Security Device Manager overview.

This chapter covers the following topics:

  • ISR overview and providing secure administrative access: This section describes methods of securely accessing a router prompt for purposes of administration. Additionally, this section provides an overview of the Cisco Integrated Services Router (ISR) line of routers.
  • Cisco Security Device Manager overview: This section examines the Cisco Security Device Manager (SDM) interface. The graphical interface provided by SDM allows administrators to configure a variety of router features using a collection of wizards and other configuration aids, which use best-practice recommendations from the Cisco Technical Assistance Center (TAC).

In addition to Cisco firewall, virtual private network (VPN), and intrusion prevention system (IPS) appliances that can sit at the perimeter of a network, Cisco IOS routers offer perimeter-based security. For example, the Cisco Integrated Services Routers (ISR) can be equipped to provide high-performance security features, including firewall, VPN termination, and IPS features, in addition to other services such as voice and quality-of-service (QoS) services. This chapter introduces various ISR models.

Because perimeter routers can be attractive targets for attack, they should be configured to secure administrative access. Therefore, this chapter also discusses specific approaches to "harden" administrative access to ISRs.

Configuring advanced ISR router features can be a complex process. Fortunately, many modern Cisco routers can be configured using the graphical Cisco Security Device Manager (SDM) interface. SDM contains multiple wizard-like configuration utilities, which are introduced in this chapter.

"Do I Know This Already?" Quiz

The "Do I Know This Already?" quiz helps you determine your level of knowledge of this chapter's topics before you begin. Table 3-1 details the major topics discussed in this chapter and their corresponding quiz questions.

Table 3-1. "Do I Know This Already?" Section-to-Question Mapping

Foundation Topics Section


ISR Overview and Providing Secure Administrative Access

1 to 10

Cisco Security Device Manager Overview

11 to 13

  1. Which of the following are considered IOS security features? (Choose four.)

    • a. Stateful firewall
    • b. MARS
    • c. IPS
    • d. VRF-aware firewall
    • e. VPN
    • f. ACS
  2. Some ISRs include a USB port, into which a flash drive can connect. What are three common uses for the flash drive? (Choose three.)

    • a. Storing configuration files
    • b. Storing a digital certificate
    • c. Storing a copy of the IOS image
    • d. Storing a username/password database
  3. The enable secret password appears as an MD5 hash in a router's configuration file, whereas the enable password is not hashed (or encrypted, if the password-encryption service is not enabled). Why does Cisco still support the use of both enable secret and enable passwords in a router's configuration?

    • a. Because the enable secret password is a hash, it cannot be decrypted. Therefore, the enable password is used to match the password that was entered, and the enable secret is used to verify that the enable password has not been modified since the hash was generated.
    • b. The enable password is used for IKE Phase I, whereas the enable secret password is used for IKE Phase II.
    • c. The enable password is considered to be a router's public key, whereas the enable secret password is considered to be a router's private key.
    • d. The enable password is present for backward compatibility.
  4. What is an IOS router's default response to multiple failed login attempts after the security authentication failure command has been issued?

    • a. The login process is suspended for 10 seconds after 15 unsuccessful login attempts.
    • b. The login process is suspended for 15 seconds after 10 unsuccessful login attempts.
    • c. The login process is suspended for 30 seconds after 10 unsuccessful login attempts.
    • d. The login process is suspended for 10 seconds after 30 unsuccessful login attempts.
  5. What line configuration mode command would you enter to prevent a line (such as a console, aux, or vty line) connection from timing out because of inactivity?

    • a. no service timeout
    • b. timeout-line none
    • c. exec-timeout 0 0
    • d. service timeout default
  6. An IOS router's privileged mode, which you can access by entering the enable command followed by the appropriate password, has which privilege level?

    • a. 0
    • b. 1
    • c. 15
    • d. 16
  7. How is a CLI view different from a privilege level?

    • a. A CLI view supports only commands configured for that specific view, whereas a privilege level supports commands available to that level and all the lower levels.
    • b. A CLI view can function without a AAA configuration, whereas a privilege level requires AAA to be configured.
    • c. A CLI view supports only monitoring commands, whereas a privilege level allows a user to make changes to an IOS configuration.
    • d. A CLI view and a privilege level perform the same function. However, a CLI view is used on a Catalyst switch, whereas a privilege level is used on an IOS router.
  8. To protect a router's image and configuration against an attacker's attempt to erase those files, the Cisco IOS Resilient Configuration feature keeps a secure copy of these files. What are these files called?

    • a. The bootset
    • b. The configset
    • c. The backupset
    • d. The backup-config
  9. When you configure Cisco IOS login enhancements for virtual connections, what is the "quiet period"?

    • a. The period of time between successive login attempts
    • b. A period of time when no one is attempting to log in
    • c. The period of time in which virtual login attempts are blocked, following repeated failed login attempts
    • d. The period of time in which virtual logins are blocked as security services fully initialize
  10. In the banner motd # command, what does # represent?

    • a. A single text character that will appear as the message of the day
    • b. A delimiter indicating the beginning and end of a message of the day
    • c. A reference to a system variable that contains a message of the day
    • d. The enable mode prompt from where the message of the day will be entered into the IOS configuration
  11. What Cisco IOS feature provides a graphical user interface (GUI) for configuring a wide variety of features on an IOS router and also provides multiple "smart wizards" and configuration tutorials?

    • a. QPM
    • b. SAA
    • c. SMS
    • d. SDM
  12. What are two options for running Cisco SDM? (Choose two.)

    • a. Running SDM from a router's flash
    • b. Running SDM from the Cisco web portal
    • c. Running SDM from within CiscoWorks
    • d. Running SDM from a PC
  13. Which of the following are valid SDM configuration wizards? (Choose three.)

    • a. Security Audit
    • b. VPN
    • c. ACS
    • d. NAT
    • e. STP
2. Foundation Topics | Next Section

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