Modules 14 and 15 Review
Which three protocols operate at the application layer of the TCP/IP model?
FTP POP3 DHCP
What is a common protocol that is used with peer-to-peer applications such as WireShare, Bearshare, and Shareaza?
Gnutella
Which application layer protocol uses message types such as GET, PUT, and POST?
HTTP
The application layer of the TCP/IP model performs the functions of what three layers of the OSI model?
Session Presentation Application
Fields used in a UDP segment header?
Source Port Destination Port Length Checksum
What is a characteristic of UDP?
UDP reassembles the received datagrams in the order they were received.
In what networking model would eDonkey, eMule, BitTorrent, Bitcoin, and LionShare be used?
peer-to-peer
What is a key characteristic of the peer-to-peer networking model?
resource sharing without a dedicated server
What are the responsibilities of the transport layer?
- Tracking the individual communication streams between applications on the source and destination hosts - Segmenting data at the source and reassembling the data at the destination - Identifying the proper application for each communication stream through the use of port numbers - Multiplexing the communications of multiple users or applications over a single network - Managing the reliability requirements of applications
A PC is downloading a large file from a server. The TCP window is 1000 bytes. The server is sending the file using 100-byte segments. How many segments will the server send before it requires an acknowledgment from the PC?
10 segments
A client creates a packet to send to a server. The client is requesting POP3 service. What number will be used as the destination port number in the sending packet?
110
A client creates a packet to send to a server. The client is requesting SMTP service. What number will be used as the destination port number in the sending packet?
25
A PC that is communicating with a web server has a TCP window size of 6,000 bytes when sending data and a packet size of 1,500 bytes. Which byte of information will the web server acknowledge after it has received two packets of data from the PC?
3001
A client creates a packet to send to a server. The client is requesting HTTPS service. What number will be used as the destination port number in the sending packet?
443
A PC that is communicating with a web server has a TCP window size of 6,000 bytes when sending data and a packet size of 1,500 bytes. Which byte of information will the web server acknowledge after it has received three packets of data from the PC?
4501
A PC that is communicating with a web server has a TCP window size of 6,000 bytes when sending data and a packet size of 1,500 bytes. Which byte of information will the web server acknowledge after it has received four packets of data from the PC?
6001
A client creates a packet to send to a server. The client is requesting TFTP service. What number will be used as the destination port number in the sending packet?
69
A client creates a packet to send to a server. The client is requesting HTTP service. What number will be used as the destination port number in the sending packet?
80
Which scenario describes a function provided by the transport layer?
A student has two web browser windows open in order to access two web sites. The transport layer ensures the correct web page is delivered to the correct browser window.
Which protocol is used by a client to communicate securely with a web server?
HTTPS
What is an example of network communication that uses the client-server model?
A workstation initiates a DNS request when the user types www.cisco.com in the address bar of a web browser.
Which flag in the TCP header is used in response to a received FIN in order to terminate connectivity between two network devices?
ACK
Which OSI layer provides the interface between the applications used to communicate and the underlying network over which messages are transmitted?
Application
Which layer in the TCP/IP model is used for formatting, compressing, and encrypting data?
Application
Which two types of applications are best suited for UDP?
Applications that handle reliability themselves Applications that can tolerate some data loss, but require little or no delay
What do the client/server and peer-to-peer network models have in common?
Both models support devices in server and client roles.
What is true about the Server Message Block protocol?
Clients establish a long term connection to servers.
Which field in the TCP header indicates the status of the three-way handshake process?
Control bits
Which protocol or service uses UDP for a client-to-server communication and TCP for server-to-server communication?
DNS
What are two characteristics of peer-to-peer networks?
Decentralized resources Resource sharing without a dedicated server
A manufacturing company subscribes to certain hosted services from its ISP. The services that are required include hosted world wide web, file transfer, and e-mail. Which protocols represent these three key applications?
FTP HTTP SMTP
What are two roles of the transport layer in data communication on a network?
Identifying the proper application for each communication stream Tracking the individual communication between applications on the source and destination hosts
How are port numbers used in the TCP/IP encapsulation process?
If multiple conversations occur that are using the same service, the source port number is used to track the separate conversations.
What does a client do when it has UDP datagrams to send?
It just sends the datagrams.
Which applications or services allow hosts to act as client and server at the same time?
P2P applications
What kind of port must be requested from IANA in order to be used with a specific application?
Registered port
What is an advantage of SMB over FTP?
SMB clients can establish a long-term connection to the server.
Which two protocols may devices use in the application process that sends email?
SMTP DNS
Which three application layer protocols use TCP?
SMTP FTP HTTP
What information is used by TCP to reassemble and reorder received segments?
Sequence numbers
A client application needs to terminate a TCP communication session with a server. What are the steps in the order that they will occur?
Step 1 - Client sends FIN Step 2 - Server sends ACK Step 3 - Server sends FIN Step 4 - Client sends ACK
Which three statements describe a DHCP Discover message?
The destination IP address is 255.255.255.255. The message comes from a client seeking an IP address. All hosts receive the message, but only a DHCP server replies.
Which three statements characterize UDP?
UDP provides basic connectionless transport layer functions. UDP relies on application layer protocols for error detection. UDP is a low overhead protocol that does not provide sequencing or flow control mechanisms.
In what two situations would UDP be better than TCP as the preferred transport protocol?
When a faster delivery mechanism is needed When applications do not need to guarantee delivery of the data
Which two fields are included in the TCP header but not in the UDP header?
Window Sequence Number
Why does HTTP use TCP as the transport layer protocol?
because HTTP requires reliable delivery
Which networking model is being used when an author uploads one chapter document to a file server of a book publisher?
client/server
What important information is added to the TCP/IP transport layer header to ensure communication and connectivity with a remote network device?
destination and source port numbers
Which factor determines TCP window size?
the amount of data the destination can process at one time
What type of information is contained in a DNS MX record?
the domain name mapped to mail exchange servers
What is the function of the HTTP GET message?
to request an HTML page from a web server
What characteristics are associated with UDP sessions?
· Destination devices will not acknowledge received data · Headers use very little overhead and cause minimal delay.
A client creates a packet to send to a server. The client is requesting SNMP service. What number will be used as the destination port number in the sending packet?
161
A client creates a packet to send to a server. The client is requesting FTP service. What number will be used as the destination port number in the sending packet?
21
A client creates a packet to send to a server. The client is requesting SSH service. What number will be used as the destination port number in the sending packet?
22
A client creates a packet to send to a server. The client is requesting telnet service. What number will be used as the destination port number in the sending packet?
23