C H A P T E R 2

General Networking Topics

This chapter covers general networking concepts listed in the CCIE Security blueprint for the written exam. The CCIE blueprint lists some example topics that define general networking, including switching, TCP/IP, routed and routing protocols, PPP, ISDN, and asynchronous communications.

The CCIE Security written exam contains approximately 50 percent security questions and approximately 50 percent general networking questions. This chapter prepares you for the general networking questions. Although the CCIE Security written exam blueprint lists some specific networking topics, it does not, for example, mention Frame Relay, which might appear on the exam. This chapter covers many of the listed and a few of the unlisted general networking topics.

Although these topics are not extensively defined in the blueprint, the CCIE Security written exam might include topics taken from the CCIE Routing and Switching written exam blueprint. This chapter endeavors to cover all bases and provide quality test examples to ensure that you are well prepared to tackle the general networking questions you encounter in the examination.

This chapter covers the following topics:

•Networking basics—The OSI model, concepts, and functions. Topics include the seven layers of the OSI model and common examples (TCP/IP).

•Switching and bridging—The process today’s networks use to switch packets and traditional bridging methods. Virtual LANs, spanning tree, and Ethernet Channel are discussed.

•Routing IP—The most widely used routed protocol in today’s Internet, IP, and the routing protocols available on Cisco routers, such as RIP, EIGRP, OSPF, and BGP. IOS commands and configuration examples demonstrate the power of routing IP on Cisco routers.

•PPP, ISDN, Frame Relay, IP Multicast, and Async—Two of the most widely used dialup protocols are PPP and ISDN. Frame Relay is covered briefly to ensure that you have a good understanding of the common terminology used in today’s networks. IP multicast and async protocols are also covered.

“Do I Know This Already?” Quiz 13

5IP operates at what layer of the OSI model?

a.Layer 1

b.Layer 2

c.Layer 3

d.Layer 4

e.Layer 5

f.Layer 6

g.Layer 7

6On which layer of the OSI model is data commonly referred to as segments?

a.Layer 4

b.Layer 3

c.Layer 2

d.Layer 1

7On which layer of the OSI model is data commonly referred to as packets?

a.Layer 1

b.Layer 2

c.Layer 4

d.Layer 3

8Which layer of the OSI model transmits raw bits?

a.Layer 1

b.Layer 2

c.Layer 3

d.Layer 4

9Which of the following protocols is not routable?

a.IP

b.IPX

c.NetBEUI

d.NetBIOS

“Do I Know This Already?” Quiz 15

15Which of the following are the four possible states of spanning tree?

a.Listening, learning, blocking, broadcasting

b.Listening, learning, blocking, connecting

c.Discovering, learning, blocking, connecting

d.Listening, learning, blocking, forwarding

16How many bits make up an IP address?

a.64 bits

b.48 bits

c.32 bits

d.24 bits

e.8 bits

17Identify the broadcast address for the subnet 131.108.1.0/24.

a.131.108.1.1

b.131.108.1.254

c.131.108.1.255

d.131.108.1.2

e.More data required

18Convert the following address to binary: 131.1.1.1/24

a.10000011.1.1.1

b.10000011.00000010.1.1

c.10000011.1.1.01010101

d.10000011.1.1.11111111

“Do I Know This Already?” Quiz 17

23Which of the following are multicast addresses? (Choose all that apply.)

a.224.0.0.5

b.224.0.0.6

c.221.0.0.5

d.192.1.1.1

e.131.108.1.1

24Which of the following routing protocols does not support VLSM?

a.RIPv1

b.RIPv2

c.OSPF

d.EIGRP

e.BGP

25What is the source TCP port number when a Telnet session is created by a PC to a Cisco router?

a.23

b.Not a known variable

c.21

d.20

e.69

26What best describes the ARP process?

a.DNS resolution

b.Mapping an IP address to a MAC address

c.Mapping a next-hop address to outbound interface on a Cisco router

d.Both a and b

27If two Cisco routers are configured for HSRP and one router has a default priority of 100 and the other 99, which router assumes the role of active router?

a.The default priority cannot be 100.

b.The router with a higher priority.

c.The router with the lowest priority.

d.Neither router because Cisco routers do not support HSRP; only clients do.

“Do I Know This Already?” Quiz 19

32What is the BGP version most widely used today?

a.1

b.2

c.3

d.4

e.5

f.6

33What is the destination port number used in a Telnet session?

a.23

b.69

c.21

d.161

34In what fields does the IP checksum calculate the checksum value?

a.Data only

b.Header and data

c.Header only

d.Not used in an IP packet

35The TCP header checksum ensures integrity of what data in the TCP segment?

a.The data only.

b.The header only.

c.The data and header.

d.There are no TCP header checksums; IP covers the calculation.

36ISDN BRI channels are made up of what?

a.1 × 64 kbps channel and one D channel at 64 kbps

b.2 × 64 kbps channels and one D channel at 64 kbps

c.2 × 64 kbps channels and one D channel at 16 kbps

d.32 × 64 kbps channels and one D channel at 16 kbps

20 Chapter 2: General Networking Topics

37What services can ISDN carry?

a.Data only

b.Data and voice only

c.Voice and video

d.Data, voice, and video

38Place the following steps in the correct order for PPP callback, as specified in RFC 1570.

1.A PC user (client) connects to the Cisco access server.

2.The Cisco IOS Software validates callback rules for this user/line and disconnects the caller for callback.

3.PPP authentication is performed.

4.Callback process is negotiated in the PPP link control protocol (LCP) phase.

5.The Cisco Access Server dials the client.

a.1, 2, 3, 4, 5

b.1, 3, 2, 5, 4

c.1, 4, 5, 3, 2

d.5, 4, 3, 2, 1

39What hardware port is typically designed to connect a Cisco router for modem access?

a.The console port

b.The vty lines

c.The auxiliary port

d.The power switch

e.The Ethernet interface

40The AS5300 series router can support which of the following incoming connections?

a.Voice

b.Dialup users via PSTN

c.ISDN

d.All the above