Assignment: Network Routing and Switching

PART A

Question 1

An organisation has been granted a block of addresses with the mask /22. If the organisation creates 8 equal-sized subnets, how many addresses (including the special addresses) are available in each subnet? Show your calculations.

Question 2

Give an example of a valid classful address that has a mask of 255.255.0.0

Question 3

Briefly explain the function of "path MTU discovery" in IPv6 routing.

Question 4

What is the size of an IPv4 header with 12 bytes of options?

Question 5

TCP/IP uses various types of addresses. What type of address is the address 210.77.124.12:51200 ?

Question 6

Briefly explain what is an ephemeral port number, and its function in TCP/IP communications.

Question 7

In your own words, briefly explain the function of the expiration timer in RIP.

Question 8

What is the primary function of DNS servers?

Question 9

In wireless networking, what is an Extended Service Set (ESS)?

Question 10

Explain when do routers forward packets out through the default route?

Question 11

Briefly explain why routers consult ARP during the forwarding process.

Question 12

What is the purpose of the TTL field in the base header of an IPv4 datagram?

Question 13

List three differences between UDP and TCP.

Question 14

In an IPv6 datagram, what are extension headers and where are they located?

PART B

Question 1

Consider the following block of classless addresses: 145.87.117.3/29

Identify the addresses in this range that would be used as the network address, those that can be used by network hosts, and the direct broadcast address.

Question 2

A company has been granted a block of addresses which starts at 200.100.20.0/25. Create the following 6 subnets for this company by calculating the subnet address for each subnet.

(a) 2 subnets with 32 addresses each
(b) 4 subnets with 16 addresses each

Question 3

A router receives a packet. List three of the logical processes the router would perform in processing that packet.

Question 4

The figure below shows the configuration of a hypothetical section of the Internet.

Construct the routing table of router R3 for this configuration by copying and completing the following table in the Examination Answer Booklet.

PART C

Question 1

Organisation-A is a large enterprise that has one class-A network address for all its needs.

Discuss the addressing problem that Organisation-A could face with its one class-A network and how it could use subnetting to help it to overcome that problem.

How would the situation be different if Organisation-A had gotten a classless (CIDR) address instead? (3 marks)

Question 2

Name one distance vector routing protocol and one link state routing protocol. Compare the two protocols in terms of the cost metrics they use.

Question 3

The period between the phasing out of IPv4 and the general adoption of IPv6 is referred to as the "transition period". Describe the main methods being developed or proposed to allow IPv4 and IPv6 to run concurrently during this period.

Question 4

In wireless network architecture, the Basic Service Set (BSS) has two possible formats. Identify these two formats and briefly explain the difference between them.