Unit 1 Chapter 2 Test

Which of the following statements are true about routers and routing on the Internet. Choose two answers.

• Protocols ensure that a single path between two computers is established before sending packets over it.

• Routers are hierarchical and the "root" router is responsible for communicating to sub-routers the best paths for them to route internet traffic.

• A packet traveling between two computers on the Internet may be rerouted many times along the way or even lost or "dropped".

• Routers act independently and route packets as they see fit.

The various protocols in use on the internet are said to operate in layers in which the protocol(s) at each layer solve one problem related to networked communication, and higher layers are built on top of, and rely on, the lower layers to do their jobs.

From the list provided choose the two (2) answers that correctly describe which internet protocol relies on the other. For example: if protocol A relies on protocol B, it means that A is a higher level protocol than B, and thus protocol B must exist and work properly in order for protocol A to do its job.

Select two answers.

• TCP/IP relies on HTTP

• HTTP relies on TCP/IP

• DNS relies on TCP/IP

• TCP/IP relies on DNS

A school starts tracking which websites each computer in the school is visiting by monitoring the packets leaving the school. A sample of the information they have collected appears below:

IP Address Time URL.........

1.1.1.1 11:05:23.22 example.com

1.5.1.8 11:05:29.71 news.com

1.1.5.1 11:06:13.48 sports.com

1.5.1.8 11:08:09.95 example.com......... 1.1.5.1 17:04:29.20 news.com

• Which students are visiting social media sites from school

• Which classes are assigning the most homework using the computers

• Which programs students are running on the lab computers

• Which websites are most frequently visited before and after school hours from a school computer

Which of the following BEST describes how protocols on the Internet (e.g. IP, TCP, HTTP) make use of abstraction to accomplish their respective purposes?

• High level protocols take into account specific implementation details of lower level protocols to ensure they are compatible.

• Low level protocols can provide functionality to high level protocols without revealing the details of how this is accomplished.

• Low level protocols are written in binary while high level protocols are written in hexadecimal.

• High level protocols can take on the role of a low level protocol in the event of failure in the system.

According to the domain name system (DNS), which of the following is a subdomain of the domain example.com?

• about.example.com

• example.co.uk

• example.com.org

• example.org

Which of the following is NOT true about TCP/IP packets?

• Packets are numbered so if they arrive out of order the message can be reassembled.

• TCP guarantees that no packets are ever dropped

• Packets can be routed on different paths from sender to receiver.

• Messages are broken into packets to improve reliability of the internet

The Internet Engineering Task Force (IETF) defines the protocols and standards for how the Internet works. The members of the IETF are:

• An International coalition of government agencies who oversee the Internet in their countries.

• A collection of the leaders of the Tier 1 Internet service providers.

• A loosely organized collection of citizens and engineers.

• Political leaders and heads of state.

• There are no members. IETF is an "organization" in name only.

How does a computer resolve a domain name into an IP address?

• It asks a DNS server for the corresponding IP address

• It scans addresses until it finds the one it's looking for

• It uses a Border Gateway Protocol to get the address from a nearby computer.

• It creates an IP address for the domain, and shares it with the closest DNS.

The figure represents a network of physically linked computers labeled A through F. A line between two computers indicates that the computers can communicate directly with each other. Any information sent between two computers that are not directly connected must go through at least one other computer. The weight or cost of sending information from one computer to another is indicated by the number above the line.

For example, information can be sent directly between computers A, and B and will cost 5. Information sent between computers A and D must go through either computer C (with total cost 5), or through computer B (with total cost 8)

Question:

Computer A sends a packet intended to reach computer F. Along its path it arrives at Computer C. Which computer should Computer Cforward the packet to in order to use the most cost effective path?

• Computer A

• Computer B

• Computer D

• Computer F

The world is currently in a transition to using IPv6, a newer version of the IP protocol that uses 128-bit addresses instead of 32-bit addresses used by IPv4. What is the main problem that IPv6 was created to solve?

• 32-bit addresses could not accommodate the increased size and amount of data traveling on the Internet as it has grown in popularity

• IPv6 will allow problems with IPv4's address hierarchy to be resolved

• IPv4 proved unreliable in some cases where network redundancy could not be ensured

• 32-bit addresses could not ensure that every internet-connected device can receive a unique IP address