Network + 2009 Q&a

POP3 (Post Office Protocol version 3), IMAP4 (Internet Message Access Protocol version 4), and SMTP (Simple Mail Transfer Protocol) are the protocols used for email traffic. POP3 is used to retrieve emails from a mail server, IMAP4 is used to access and manage emails on a mail server, and SMTP is used to send emails between mail servers. These protocols work together to ensure the proper functioning of email communication.

TCP (Transmission Control Protocol) is considered a connection-oriented protocol because it establishes a reliable and dedicated connection between the sender and receiver before transferring data. It ensures that all data packets are received in the correct order and without errors. TCP provides features like flow control, congestion control, and error detection, making it suitable for applications that require a guaranteed delivery of data, such as web browsing, email, and file transfer. UDP (User Datagram Protocol) is a connectionless protocol, meaning it does not establish a dedicated connection and does not guarantee the delivery of data packets. SPX (Sequenced Packet Exchange) is a protocol used in Novell NetWare networks. IP (Internet Protocol) is a network layer protocol responsible for addressing and routing packets, but it does not establish connections.

The correct answer is that the Transmission Control Protocol (TCP) protocol has the ability to recover from lost/corrupted network packets during transmission. TCP uses a mechanism called automatic repeat request (ARQ) to ensure reliable delivery of data. When a packet is lost or corrupted, TCP detects the error and requests the sender to retransmit the packet. This process continues until the packet is successfully received, ensuring that no data is lost during transmission. TCP also uses sequence numbers and acknowledgments to ensure that packets are delivered in the correct order.

FTP (File Transfer Protocol) is the correct answer because it is commonly used to access and transfer files between a client computer and a remote server. FTP allows users to authenticate themselves and establish a connection with a remote server to upload, download, or manipulate files. It provides a set of commands that enable users to navigate directories, create folders, and perform file operations on the remote server. ARP (Address Resolution Protocol) is used for mapping IP addresses to MAC addresses, SIP (Session Initiation Protocol) is used for initiating and terminating multimedia communication sessions, and NTP (Network Time Protocol) is used for synchronizing the time on network devices.

FTP (File Transfer Protocol) would occur at the application layer of the OSI model. The application layer is responsible for providing network services to user applications. FTP is a protocol that allows for the transfer of files between a client and a server over a network. It provides a set of commands and responses that enable users to upload, download, and manage files on a remote server.

PAP (Password Authentication Protocol) is the correct answer because it is an authentication protocol that transmits passwords in plain text over the internet. This makes it less secure compared to other protocols like CHAP (Challenge-Handshake Authentication Protocol) and Kerberos, which use more secure methods to transmit passwords. RADIUS (Remote Authentication Dial-In User Service) is a protocol used for centralized authentication, authorization, and accounting for remote access.

LDAP (Lightweight Directory Access Protocol) is a protocol used by several different operating systems to authenticate resources such as computers, users, and printers. It provides a standardized way for accessing and managing directory information, allowing organizations to centrally store and manage user credentials and other resource information. LDAP is commonly used in enterprise environments for authentication and authorization purposes, allowing users to access resources based on their credentials stored in a central directory. It is a widely adopted protocol and is supported by various operating systems and applications.

NNTP (Network News Transfer Protocol) is the correct answer for this question. NNTP is a protocol used for connecting clients to a news server. It is specifically designed for the distribution, retrieval, and posting of news articles in Usenet newsgroups. NNTP allows clients to connect to a news server and access newsgroups to read and post articles. This protocol is commonly used by newsreader software to access and participate in online discussions and access news articles from various newsgroups.

The IP address 192.168.1.125 is a private IP address, which means it is not routable across the internet. Private IP addresses are used within local networks and cannot be directly accessed from outside the network. Therefore, the user is unable to establish an FTP connection to the home computer from the PC at work.

PAP (Password Authentication Protocol) is a protocol that allows user names and passwords to be transmitted as clear-text. Unlike other protocols like RADIUS, CHAP, and SSH, PAP does not encrypt the user credentials, making it less secure. This lack of encryption makes PAP vulnerable to eavesdropping and unauthorized access.