Network Architecture and IP Networking Questions

Questions:

Q1:  In the following questions, circle all the correct answers from the list.
 
1A frame passes from a station through two Layer 2 switches, then through a router, then through two more switches, and then to the destination station. During the communication, there are:
a. Two Physical layer links
b. Six Ethernet Frames
c. Two Ethernet Frames
d. At least two dropped packets (one in each direction)
e. Six Physical layer links
2If the source and destination hosts are separated by four networks, when the source host sends a packet, the Layer 2 data link layer destination address in the frame sent by the host will be:
a. The address of the first network router.
b. The address of the destination host.
c. The address of the first LAN switch.
d. The address of the DNS server
e.   The address of the DHCP server

3If 123.24.31.8 is an IP address of a host in a /20 network (i.e. a network with 20 bits allocated to the network portion), the network portion of the IP address is:
a. 123.24.24.0
b.   123.24.10.0
c. 123.24.31.0
d. 123.24.16.0
e. 123.24.8.0

4You design an IP network address architecture with a network mask of 255.255.0.0 and allocate 2 bits for the subnets in this network.  The host with address 10.5.199.15 is a computer in your fourth subnet (with both subnet bits set at 1).  Of the following hosts, identify the one(s) that are not in the same subnet:
a. 10.5.196.1
b. 10.5.190.10
c. 10.5.253.250
d. 10.5.138.253
e. 10.5.199.200
5When an HTTP server with an IP address of 60.4.33.50 transmits, its source SOCKET will be represented as:
a. 60.4.33.50:25
b. 60.4.33.50:1030
c. 60.4.33.50:75
d. 60.4.33.50:100
e. None of the above.

6WANs are designed:
a. To provide site-to-site networking.
b. To provide operations continuity for the enterprise
c. To provide enterprise services efficiently
d  To control the total IT costs for the enterprise
e.  To provide remote enterprise access to individuals working from home

7From an IP transport, switching and routing perspective:  

a. LANs exist only within a city while WANs exist between cities
b. Both LANS and WANs may have L2 and L3 devices
c. LANS have only L2 devices while WANs have only L1 devices
d. LANs are primarily within a building/campus while WANs provide interconnections between buildings/campuses
e. LANS have L2 devices and clients only, WANs have L3 devices and servers

8When a Virtual Desktop (VDT) environment is deployed in an organization, all enterprise users have
a. desktops that all have the same applications
b. desktop with client images located on centralized servers
c. desktops with a pre-set limit on processing power and memory
d. desktops for download of applications when needed and deletion of residual data immediately after use
e. Tablets that can provide mobility by using wireless access only

9Which of these is/are not a characteristic of public cloud computing?
a. has one tenant with many applications with each application running on fixed, separate virtual machine instances
b. provides metered service
c. has instances at multiple geographical locations, with each instance operating as an island for customers within the geographic region
d. is scalable
e. links multiple private enterprises by providing a common switching point for enterprise applications

10Which of the following statements are true about the IaaS, PaaS and SaaS cloud service delivery models:
a. SaaS has more CSP provided functionalities/features than the other two
b. SaaS is the most viable option for an enterprise to migrate its services
c. For migration of a legacy, internally developed service, an enterprise will most likely use IaaS or PaaS, but not SaaS
d. DaaS is the one solution that can meet all enterprise needs
e. IaaS will require multiple CSP cloud locations to have the necessary elastic capabilities for enterprise services
Q2:  Ethernet and LANs
a)Draw a simple diagram to show a Hierarchical Layer 2 switched network architecture on a LAN.  In such a hierarchical switch network how many possible paths can there be between any two hosts?

b)Two Layer 2 switches require 2 Gb/s link between them to effectively handle all the traffic between them.  If the switches have 48, 100 Mb/s line side ports and 4, 1 Gb/s trunk side ports, how would you connect them?  Name and explain the technique you would use to get the required BW on the link between the switches.

Link Aggregation

c)The figure below shows a LAN inside a small company’s premises.  It is all located on a single floor (200 ft. long and 100 ft. wide) in a high-rise building. The switches are placed on available spaces around the office floor – they are not in data closets.  There are two data closets available on the floor, but these are used mainly for storage.  One of the closets has the building external router placed on top of a small table.

iIdentify 3 issues (problems) that you see with the current LAN structure.  Provide a brief explanation of why each item is an issue.
iiHow would you modify the LAN architecture to fix the issues?  Draw a small sketch to show the new LAN structure

Q3:  IP Networking
 You have a small organization with 5 subnets.  Each of the subnet has about 50 or so hosts.  In order to allow for a small growth in number of hosts in the subnets, you decide to allocate six (6) bits for the host component of the IP address.        
(a) How many minimum numbers of bits will you need to assign to the subnet portion of your IP address (assume that the number of subnets will not increase)?
(b) Assuming you use the minimum number of bits for the subnet portion, what is the mask (use the dot decimal notation) for just the network part (i.e. excluding the subnet) of your IP addresses?   What is the mask for the (network+subnet) part of your IP addresses?
255.255.254.0 
255.255.255.192
(c) The private IP address of the first host in one of your subnets is 10.128.128.65.  What is the IP address (in dot decimal notation) of the subnet containing the host?
10.128.128.64
(d) What are the IP addresses (in dot decimal notation) that you can have for the remaining four subnets in your organization
10.128.128.128
10.128.128.192
10.128.129.0
10.128.129.64
(d)  Can the IP address 10.128.129.1 be a valid address of one your hosts?  Will it be in the same subnet as the host with the address 10.128.128.65 listed above?