intro computer networks

correct display filter that shows all TCP traffic running on port 80 on Wireshark?

tcp and tcp.port == 80

Which of the following terms has the meaning of this statement: taking a packet arriving on one of a host's incoming links and forwards it to one of the host's outgoing links according to its destination

packet switches

(T/F) In packet-switching networks, the computing devices are interconnected through communication links and packet switches

True

The following networks are the same as Wi-Fi except for?

Ethernet LANs

Which of the following is the correct display filter that shows everything but excludes FTP traffic on Wireshark?

not ftp

In packet-switched networks, the resources needed along a path to provide for communication between the end systems are reserved for the duration of the communication session

False

You can use the Wireshark feature under which of the following menu items to recover a file for captured FTP data packets?

Statistics -> conversations

Which of the following Wireshark features is to recover a file for captured FTP data packets?

Follow Stream

Which of the following Wireshark display filters gets all HTTP and FTP traffic with 192.168.1.33 being either the source IP or the destination IP?

(http or ftp) and ip.addr == 192.168.1.33

Which of the following is NOT defined in a network protocol?

the length of messages sent and received among networking hosts

Which of the following Wireshark display filters shows all the traffic except ARP, DNS and DHCP?

not (arp or dns or dhcp)

Which of the following is the correct display filter that shows all Web traffic on Wireshark?

http or https

Which of the following is NOT a correct statement for the Internet?

The Internet is a computer network that interconnects billions of computing devices via coaxial cable, copper wire, or optical fiber

(T/F) A packet is stored at a router until it has fully arrived

True

(T/F) Wireshark is a packet sniffer that can be used to capture and analyze network packets.

True

Which of the following is NOT true about the layered architecture used in computer networking?

Layer architecture is ONLY used in the TCP/IP model, NOT in the OSI model

Which layer in the OSI model allows the two communicating applications to interpret the meaning of data exchanged?

presentation layer

Which layer in the OSI model is designed to minimize loss of data during large data exchange?

session layer

Which of the following application-layer protocols is on top of UDP?

SNMP

Which of the following is NOT true about the layered architecture in computer networking?

IP datagram

The data unit at the transport layer is

segment

The data unit at the data link layer is

frame

The data unit at the physical layer is

raw bits

Which of the following is NOT a reason why the OSI model is preferred to use when we study network security issues?

the more layers the better in any protocol models

Layering provides modularity, which makes it much easier to change implementation of services provided at each layer, and keep the remainder of the system unchanged if a layer's implementation is changed

True

What is the TCP/IP protocol model designed for?

HTTPS

Which of the following statements is NOT true about TCP?

delivery of messages to their destinations are not guaranteed

Comparing TCP with UDP, which of the following is NOT true?

TCP is more efficient

What command can be used to display the IP address, subnet mask and default gateway in Windows?

ipconfig

What command with which switch can be used to display the IP address, subnet mask, default gateway, DNS server, and DHCP server in Windows?

ipconfig /all

What command can be used to display the IP address, subnet mask and default gateway in Linux?

ifconfig

What command is used to lookup DNS information in both Windows and Linux?

nslookup

What command is used to display connection information of a host in Windows and Linux?

netstat

What protocol is used to determine the Layer 2 MAC address of a host when its Layer 3 IP address is known?

ARP

If a browser received a new file format from a Web server within an HTTP response page, it may not know how to interpret and display on it. The browser may

refer to a table of MIME types

HTML content type is identified by

MIME

The methods that are used to improve the performance of Web applications include the following EXCEPT FOR

Using a different browser

Typical Access Time from CPU to main memory is about

1,000,000 times faster than from CPU to hard disks

Which of the following is a new HTML 5 feature that are NOT available in HTML 4?

native audio and video support

Which of the following commands is mainly used to troubleshoot network connectivity, reachability, and name resolution?

ping

Which of the following commands can be used to make a network interface active on Linux systems?

ifconfig

Which of the following commands can be used to change the IP address of a network interface on Windows systems?

ipconfig

Which of the following is NOT a URL protocol?

snmp

What is the solution to browsers' problem of supporting a rapidly growing collection of file types?

When a server returns a page, it also returns some additional information about the page including its MIME type

(T/F) A browser plug-in extends the browser for supporting new file types

True

(T/F) Web servers can use caching and multiple threading to improve performance

True

A client browser's state is maintained by using

Cookies of a browser

What command restarts the DHCP lease process in Windows?

ipconfig /renew

Name the four steps, in order, in a successful DHCP process

-DHCP server discovery

-Receive DHCP server offer

-DHCP request from server offers

-Server DHCP acknowledgement for request confirming parameters

Which of the following statements is TRUE about HTTP request messages?

Accepts header gives the browser a chance to tell the Web server which format it wants for a resource

The following are the HTTP Request Methods in HTTP 1.0 EXCEPT FOR

PUT

The arp -a command displays

the current contents of the ARP cache table on your computer

To clear the arp cache, use the following command

arp -d

Why would an ARP frame have a destination MAC address of 00:00:00:00:00:00?

To indicate the ARP frame was broadcasted to all the hosts on the network.

What technology allows an HTTP client to retrieve individual data items from Web server to update a section of the webpage without having to reload an entire page?

AJAX

"HTTP 1.1 supports pipeline requests" means

A client browser can send the 2nd request to a Web server before the response to the 1st request has arrived

TCP uses the fast-start procedure to increase the throughput rapidly to improve the performance of data communication between two application end points

False

What command clears the DNS cache on a Windows machine?

ipconfig /flushdns

What is another name for a CNAME record?

Alias

What does an A record hold?

IPv4 address

Which of the following is NOT a network application?

Microsoft PowerPoint application

The following are reasons why DNS is needed EXCEPT FOR

Servers' IP addresses are permanent and never change

(T/F) A DNS zone is a portion of the DNS namespace that is managed by a specific organization or administrator

True

Many business computers have three distinct and worldwide unique identifiers. Which of the following does NOT belong to these unique identifiers?

the port number

(T/F) DNS namespace is hierarchical from the root down with the root is named COM

False

(T/F) A DNS server uses well-known UDP port 53 for all its UDP activities

True

To request a new IP address from a DHCP server, run the following command

ipconfig /renew

How many columns in the DNS database table?

5

Which of the following is TRUE about DNS?

DNS uses both TCP and UDP services at the trans-layer.

The figure below shows the process of a remote DNS query. At the end of Step 9 in this figure, what the local name server received from UWCS name server is

the IP address of the server "robot.cs.washington.edu"

Which of the following transport service primitives is ONLY called at the server side?

LISTEN

Which of the following transport service primitives is ONLY called at the client side?

CONNECT

(T/F) For an application with a server and several remote clients calling transport service primitives, a client first executes a CONNECT primitive, and then the server executes a LISTEN primitive

False

(T/F) If a socket is created with the socket type SOCK_STREAM, then it is a UDP socket which is connectionless

False

(T/F) After a socket is created, it should be bound to a local address (HOST, PORT) before it can listen to incoming connection requests

True

(T/F) After the listen() method is called by the server program, it is ready to accept connection requests

True

The backlog argument provided for the listen() method specifies

the maximum number of queued connections

(T/F) The return value of the socket method accept() is a pair (conn, address), where conn is a new socket object that can be used to send and receive data on the connection

True

# the Python statement below opens the file to writef = open(file, 'wb')

the file will be opened in binary mode

(T/F) The buffer size used in the socket recv() method at the server side program should be equal to the length of the data provided to the socket send() method at the client side program

True

(T/F) The port numbers used in the socket server program and client program MUST be the same

True

(T/F) In Python, to write to an existing file, you must add a parameter to the open() function:

True

(T/F) With client-server socket programming, the server program uses two sockets: one socket is used to listen for incoming connection requests, the other one performs data transfer with a client program

True

How an application at layer 5 uses the services at layer 4 in the TCP/IP model?

through a transport address which is a port number

(T/F)

# A client program with socket programming has the following Python code:

client_s.connect( (host, port ) )

# client_s represents the socket created by the client program

In the above Python statement, host should hold the IP address of the client host

False

Which of the following is an interface of data communication between the Transport layer (layer 4) and the App layer (layer 5)?

TSAP

Which of the following app-layer protocol uses the standard port 443 by default?

HTTPS

Which of the following statements is TRUE?

Both ends of a TCP connection can always release the connection if the server can receive at least one DR (Disconnect Request) sent from the client, with the help of timers and retransmission

__________ allows the sender to send multiple frames before needing the acknowledgements

Sliding window

What is the minimum size of a UDP segment?

8 bytes

What is the minimum size of a TCP segment?

20 bytes

What is the maximum length of an IP packet?

65,535 bytes

What is the size of an IP pseudo-header for IPv4?

12 bytes

Which of the following application-layer protocols always uses UDP services at the transport layer?

DHCP

Which of the following app-layer protocols runs on top of TCP?

POP-3

(T/F) The maximum size of an IP packet is 65,535 bytes. Since 65,535 − 20 (TCP header) − 20 (IP header) = 65,495, it means that we can always push 65,495 bytes of data into a TCP segment

False

Which of the following flags is TRUE if a TCP segment carries some data?

PSH

A TCP segment with the flags SYN = 1 and ACK = 1

can ONLY be sent from a server host to a client host

Which of the following flags in the TCP header is used for congestion control?

CWR

What does RIP stand for?

Routing Information Protocol