Appendix A. Answers to Chapter "Do I Know This Already?" Quizzes and Q&A Sections

"Do I Know This Already?"

1.	B
2.	B
3.	B
4.	C
5.	B
6.	A
7.	D
8.	A
9.	C
10.	D
11.	C and D
12.	B, C, D

Q&A

1.	Access devices are responsible for attaching end systems to the network and assigning them to virtual LANs (VLAN). Distribution devices are Layer 3 switches and act as intermediate devices that route between VLANs and apply traffic policies such as firewalling and QoS decisions. Core devices, also known as the backbone, provide high-speed paths between distribution elements.

2.	The enterprise campus features five sections: - Campus backbone (such as the core layer of the hierarchical model) - Building distribution - Building access - Management (overlaid resources to maintain the network) - Server farm (for enterprise services)
3.	The enterprise campus specifically calls out and describes management. The server farm describes how enterprise servers are housed, where previously there was not a standard place to put servers.
4.	The enterprise edge details the connections from the campus to the wide area. - E-commerce - Internet connectivity - Remote access (dial and VPN) - WAN (internal links)
5.	(7*6)/2 = 21
6.	6
7.	A network policy is implemented at the distribution level in the hierarchical design model.
8.	The two have few differences. A server farm is a standard switch block, but servers are usually dual-homed to two access switches.
9.	A "converged" network is a design that includes support for traditional data applications as well as newer voice and video uses.
10.	IIN describes a vision of a network that integrates network and application functionality cooperatively and allows the network to be smart about how it handles traffic to minimize the footprint of applications. SONA is the use of IIN in an enterprise environment. AON is application-oriented networking (AON) blades that make the network "application aware."
11.	SONA (Services-Oriented Network Architecture) is the application of the IIN ideas to Enterprise networks—those ideas being to develop a solid converged network foundation and then to build up application services on that. SONA breaks down the IIN functions into three layers: - Network Infrastructure, which describes a hierarchical converged network and the attached end-systems. - Interactive Services, which allocates resources to applications. - Application, which includes business policy and logic integration
12.	OSPF, EIGRP, and IS-IS
13.	Classful routing protocols communicate a prefix. The associated mask is assumed.
14.	All three protocols are wholly acceptable; however, there are some small differences between them from a support perspective. OSPF is a public standard, and is therefore supported on a wide variety of equipment. This protects against incompatibilities with legacy equipment or "vendor lock-in." On the other hand, OSPF networks are complicated to build and maintain. IS-IS, like OSPF, is a public standard. IS-IS, however, is not as commonly supported and finding equipment and personnel to support it can be challenging. Also, because it is not as commonly used, development of IS-IS has stagnated and it is not as feature-rich as OSPF. EIGRP is the easiest to configure of the three, doing many smart things automatically. EIGRP, however, is a Cisco proprietary protocol and using it locks you in to Cisco equipment. Obviously, different organizations will weigh factors such as ease of use and public standards. The "best" protocol is the one that is most appropriate for a given situation.