Ch. 2 Network Protocols

IPv6 uses ____-_____ _______ _______ to identify the hosts on the Internet.

128-bit binary numbers

IMAP operates on port _____, through which a local client can exchange email messages with an email server.

143

The file transfer process starts with a request from an FTP client. Based on the client's request, a set of commands is formed. The client request will be forwarded to the FTP server through the port ___, to which the FTP server listens.

21

By default, SSH uses port ___ for information exchange.

22

Telnet communicates with the server through port ____.

23

The SMTP client connects to the SMTP server through port ___.

25

IPv4 uses a ____-____ ______ _______ to specify the address for each network host.

32-bit binary number

For IPv4, the maximum size of an Internet packet is _______ bytes, including both the data and the header.

64k

To request a Web page, the user enters the Web page URL and presses the enter key, and the Web browser immediately sends an HTTP GET command to the Web server at port ____.

80

ARP relates an IP address with its hardware address.

Address Resolution Protocol

IPSec secures IP communication.

IP Security

The commonly used network address parameters used in DHCP are the __ _____, the _____ ______, the _______ for the default ______ and DNS _____, and so on.

IP address, subnet mask, addresses, gateway, servers

The ______ layer is the layer between the transport layer and the network interface layer.

Internet

What does ICMP stand for? Remember, it is used by network operating systems to get responses from remote hosts.

Internet Control Message Protocol

IP formats packets, called _____ packets, so that the packets can be delivered across the _______.

Internet, Internet

_____ can be used to manage the directory service that stores, organizes, and authenticates information about network users and network resources.

LDAP

_____ can be used to improve network performance, detect and correct network problems, and monitor network activities.

SNMP

____ can be used to remotely access ______ and ______ systems, or a network device such as a switch.

Telnet, UNIX, Linux

IP relies on ______ to provide the connection-oriented service to accomplish these tasks.

TCP

To accommodate heterogeneity, IP must accomplish the following tasks: Format packets with an ______ ________. Pass data from one _______ to another _______. Fragment packets into smaller packets to pass through networks that have ______ ______ transmission rates, and _______ the fragments at the ultimate destinations.

addressing scheme, network, network, low data, reassemble

The protocols in the transport layer are responsible for processing requests from the ______ layer and issuing them to the ______ layer in the TCP/IP architecture.

application, Internet

As a simple protocol, SMTP has no ______ measure to verify who is sending the message.

authentication

To improve security and performance over SMTP, we can use Enhanced Simple Mail Transer Protocol (ESMTP), which adds many features for _______, reducing _______, and ____ ______.

authentication, bandwidth, error recovery

Better than Telnet, SSH supports strong ______ and ______, which can protect the network from attacks such as _____ _____ or ____ _____ ______.

authentication, encryption, IP spoofing, IP source routing

CRC can be useful for detecting damaged _______ _______ or _______ ______ caused by hardware failure.

binary signals, binary bits

Computing and verifying the _______ for transmission error detection.

checksum

Telnet transmits data in _____. Telnet does not support ______ and _______ measures to secure the content exchanged on the network. It has been gradually replaced by more secure protocols such as _____ _____ (___).

cleartext, authentication, encryption, Secure Shcll (SSH)

The application layer takes care of the ______ between application software installed on two hosts on a network, such as a conference call or remote connection of a database server.

communication

In the application layer of the TCP/IP architecture, protocols also perform tasks such as data ______, data ________, video _______ and data ______ ______.

compression, encryption, streaming, format conversion

Unlike TCP, UDP is a protocol that does not provide mechanisms to establish a reliable _______ between two network hosts before transmitting packets.

connection

IP provides the fundamental delivery system. It uses a _________ method to deliver packets.

connectionless

During packet transmission, packets can be delayed or lost if many packets are _______ in one section of a network. Such a phenomenon is called _______ ________.

crowded, network congestion

The trailer may include an error-checking mechanism called _______ ________ ________ (CRC).

cyclic redundancy check

A header includes information about the ____ to be transmitted and the _____ to carry out the transmission.

data, network

The Internet packet is also called the _______. Two versions of IP, _____ and ______, are used on the Internet.

datagrams, IPv4, IPv6

To deliver the packets across the Internet, IP must format the packets with ________ addresses so that it will know where to deliver them. Also, to get a response from the receiver, IP must format a packet with a sender's address, known as the ______ address.

destination, source

Discarding the ______ packets mistakenly sent by TCP.

duplicate

Checking if there are transmission _________ and _________ the packets that have transmission errors or are lost during transmission.

errors, resending

Protocols included in this layer are used to _____, ______, and _____the sessions that handle requests and responses between the two hosts.

establish, terminate, manage

Like Telnet, SSH allows users to log on to a remote host, ____ _____, and _____ ____.

execute commands, transfer files.

Name three parts of a packet (according to book):

header, data unit, trailer

Because IP is designed to carry data across the Internet, it must be able to deliver a packet through _________ networks.

heterogenous

Keeping the transmitted packets _____ _______ so that the packets can be ________ back to the original file.

in order, reassembled

After the timeout period is over, TCP assumes that that the ______ is lost and ______ the packet again.

lost, sends

The advantage of IMAP is that it supports _____ _____ on the ____ side.

multiple folders, server

A frame is a packet formed by a specific ______ ________ technology in the _______ ________ layer.

network hardware, network interface

TCP divides the data to be transmitted over the network into small units called _______.

packets

The transport layer protocols have the ability to identify the ______ so that the packets can be delivered to the proper ______ of destination. _______ _____ ______ (___) and _____ _______ ________ (___) are two well-known transport layer protocols.

ports, ports, Transmission Control Protocol (TCP), User Datagram Protocol (UDP)

The protocols in the transport layer _____ the network transmission. They break the data to be transmitted into small units called _____.

prepare, packets

However, SMTP is not used to _____ messages from email servers for ______ owing to its limited ability to _____ messages at the receiving end.

receive, reading, queue

After the email messages are downloaded from the server, they will be ______ from the email server, which is a less desired feature of POP3.

removed

When a packet gets lost or delayed, TCP provides a ________ mechanism to resend the packet.

retransmit

Created in 1969, Telnet is not _____.

secure

UDP simply _____ and _____ packets from one port to another port over the network. Although UDP has a better performance than TCP, it is a less _______ protocol.

sends, receives, reliable

The disadvantage of POP3 is that it only supports a _____ ______ and does not support multiple _____ on the email server.

single inbox, folders

A header may include the ______ and _______ addresses, a _______ _______ _______, ____________ bits, a packet ______ ________, and the ______ of the packet.

source, destination, packet sequence number, synchronization, type indicator, length

TCP implements the three-way handshake with a ____ _____ _____ to establish and terminate a reliable connection between the ports hosted by two network hosts.

three-packet process

Packets are used because: The protocol and hardware in a transmission _____ to coordinate the transmission. When multiple computers share the same network media, these computers transmit packets in ____. The use of packets ensures that each computer gets _____ chances to transmit.

time, turns, equal

UDP also does not provide a ______ _______ correction mechanism.

transmission error

Controlling network congestion by determining the proper packet ______ ________ based on the network capacity.

transmission rate

TCP includes several congestion control mechanisms to resolve the network congestion problem. One of the solutions is to adjust the packet _______ _____ according to the packet ______ _______. When packets get lost or delayed during transmission, instead of resending all the missing packets immediately, TCP will resend _____ packet first.

transmission rate, loss rate, one

The transport layer protocols also handle tasks such as data _______, error ______, network ____ ______, and _______, ______, and _______ a connection between two hosts.

transmission, checking, flow control, establishing, managing, terminating

During the transmission process, controlling the flow of packets by using a ________ ________.

window mechanism

TCP provides a ______ _______ to control the flow of packets so that the receiver is not overwhelmed.

window mechanism

On a network, information exchange is carried out by the _____ protocol.

IP

Web servers use interfaces such as ____ _____ _____ (__) and ____ ____ ____ _____ _____ (___) to pass data to other applications and scripts.

Common Gateway Interface (CGI), Internet Server Application Programming Interface (ISAPI)

Name five features that make TCP such an important protocol.

Connection orientation, Point-to-point communication, complete reliability, full-duplex communication, three-way handshake connection

_____ is a protocol that can be used to automatically assign network parameters to a computer or network device.

DHCP

____ is a protocol that can be used to exchange files between computers on a network. It can be used to download file from a Web site or upload files to a Web server.

FTP

_____ is the protocol used for transferring data between Web browsers and Web servers.

HTTP

Name ten of the most commonly known network protocols in the application layer.

Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), Dynamic Host Configuration Protocol (DHCP), Simple Mail Transfer Protocol (SMTP), Post Office Protocol version 3 (POP3), Internet Message Access Protocol (IMAP), Telecommunication Network (TelNet), Secure Shell (SSH), Lightweight Directory Access Protocol (LDAP), and Simple Network Protocol (SNMP).

Like POP3, ____ can also be used for receiving email messages.

IMAP

______ is one of the protocols used for receiving email messages. Can be used to check the mail box on an email server and download email from the server for reading. Does not support sending messages.

POP3

_____ is a network protocol used to securely exchange information on the network.

SSH

What are two disadvantages of FTP?

Security and performance

_____ _____ ______ ______ (___) is a protocol used by email clients to send messages to email servers. It can also transmit email messages between two email servers.

Simple Mail Transfer Protocol (SMTP)

_______ packets and making sure that all packets _______ at the destination host.

Tracking, arrive

Similar to TCP, ______ is also a transport layer protocol used to send and receive messages over a network .

UDP