わくわくIT資格勉強記

The original network that ultimately become the Internet was called
　A. NSFNET
　B. ARPANET
　C. DoDnet
　D. DARPA

NSFNET was the follow-on network, DARPA is an organization, and DoDnet does not exist.

The primary organization behind the development of original Internet was
　A. IBM
　B. Digital Equipment Corporation (DEC)
　C. Stanford university
　D. the U.S. Department of Defense

All of the other answers are incorrect.

Which of the following was not a primary design concern during the development of the original Internet?
　A. Reliability
　B. Bandwidth
　C. Interoperability
　D. Support for diverse network media

The network needed to support diverse systems in a reliable manner over diverse media. There was not a great neet for large amounts of bandwidth.

Which of the following was not a reason TCP was superior transport protocol to NCP?
　A. Support for global addressing
　B. Support for end-to-end checksums
　C. Support for applications such as email
　D. Support for fragmentation and reassembly

NCP provided support for applications like email; it did not provide any of the features in the other answers.

Which of the following OSI layers is not paired with correct implementation?
　A. Layer 7 -- Email
　B. Layer 3 -- TCP
　C. Layer 4 -- UDP
　D. Layer 2 -- PPP

TCP is Layer 4 protocol. The other answers are incorrect.

Part of the growth of the APRANET was driven by the ability of anyone to create and disseminate information about potential protocol and applications in a particular kind of document. These documents are known as
　A. Requests For Information.
　B. Protocol Revisions.
　C. Requests For Comments.
　D. Requests For Configurations.

The other answers are incorrect.

ISPs connect to each other at well-defined network location to exchange information. These connection points are known as
　A. ISPs
　B. IXPs
　C. BGPs
　D. POPs

The other answers don't address the question.

A company that has locations throughout the country can obtain service at each location from a Tier 1, Tier 2, or Tier 3 provider. What is one reason a company might choose to connect all locations to a Tire 1 provider despite the higher costs involved?
　A. Sites at different tiers cannot communicate.
　B. Tire 3 providers don't use TCP/IP.
　C. Only Tier 1 providers provide contents.
　D. A single provider could offer SLAs to each location.

A single provider can offer SLAs because the traffic would be contained entirely within its own network; other providers can provide the service in the other answers.

Which of the following service would likely be offered by a content provider but not a service provider?
　A. Standard dial-up service
　B. Live video streaming from sports events
　C. Email service
　D. Basic Web Services

Live streaming video for sports events would clearly fall into the contens scope of service. The other service are all commonly offered by all service providers.

Which of the following accurately describes the TCP protocol?
　A. Connectionless with no guarantee of delivery
　B. Connectionless with guarantee of delivery
　C. Connection-oriented with guarantee of delivery
　D. None of the above

"Connection-oriented with guarantee of delivery" describes the basic functions of using TCP. The other answers are incorrect.

Originally, the IP protocol functions were performed by
　A. Ethernet
　B. TCP
　C. NCP
　D. ALOHANET

Originally the function of both TCP and IP were in a single TCP protocol.

When an HTTP packet needs to be forwarded over the Internet, which of the following accurately describes the order of the headers as they would be placed in front of each other in the packet (assume the orginating device is on an Ethernet network)?
　A. HTTP, IP, TCP, Ethernet
　B. HTTP, TCP, IP, Ethernet
　C. HTTP, UDP, IP, Ethernet
　D. HTTP, IP, Ethernet

The headers are placed in front of each other in order of the protocol stack from the highest layer down, so the order would be application, Layer 4(TCP), Layer 3(IP),and then Layer 2(Ethernet).

A router processing the packet described in Question 12 would need to examine and/or manipulate the headers for
　A. Ethernet only
　B. IP only
　C. TCP and IP only
　D. IP and Ethernet only

A router would remove the Ehternet (Layer 2) header, examine the IP (Layer 3) address to determine how to forward the packet, and then replace the Layer 2 header for the appropriate next-hop interface.

What would a router processing the packet described in Questtion 12 do with the Layer 2 header of the incoming packet?
　A. Remove the source Layer 2 address, add its own, and forward the packet.
　B. Remove the Layer 2 addresses and repalce them with new addresses.
　C. Remove the entire Leyer 2 header and create a new one based on the next hop interface.
　D. Leave the original Layer 2 header but forward the packet based on the destination address.

Answer B is incorrect because the next-hop interface might be a different layer technology so the routert connot simply replace addresses; it must create a new Layer 2 header. The other answers don't describe the forwarding process correctly.

Most of the OSI-created protocol are no longer in use, although a few still provide some critically important functions.Which of the following describes an OSI protocol that is still in use?
　A. OSPF
　B. LDP
　C. TP0
　D. IS-IS

IS-IS is a routing protocol developed by the ISO that is still in use in many provider network. The other answers are either not ISO protocols or are no longer in use.