NCTI IV ch 4

UDP does not use SYN and ACK packets.

A client Domain Name System (DNS) resolver wishes to resolve a Web server fully qualified domain name (FQDN) to an IP address. It sends its first message to its designated DNS server, requesting name to IP address resolution. This message contains: 1) The LAN protocol Data Link Layer header and trailer. 2) The IP header. 3) The user datagram (UDP) header. 4) The DNS resolver request. Why did the resolver send the DNS request in the first packet, rather than send an initial empty SYN packet?

Proxy ARP.

A host on the local IP network segment has data to send to another host, located on another IP network. The source host needs to resolve the destination host's IP address to a media access control (MAC) address. Which protocol might the gateway router run in order to answer the local host's address resolution protocol (ARP) request?

Broadcast

Address resolution protocol (ARP) requests are sent as which type of Ethernet frame?

Data Link

At which Open Systems Interconnection reference model (OSI/RM) layer does the physical address reside?

Domain Name System (DNS) Port 53 Hypertext transfer protocol (HTTP) Port 80 Simple Mail Transfer Protocol (SMTP) Port 25• NetBIOS session service Port 139 File transfer protocol (FTP) control Port 21 File transfer protocol (FTP) data Port 20 Telnet Port 23

Match the well known transmission control port (TCP) port numbers with the associated applications.

Port 53- Domain Name System (DNS) Port 67- BOOTP Server Port 68- BOOTP Client Port 69- Trivial File Transfer Protocol (TFTP) Port 123- Network Time Protocol (NTP) Port 161- Simple Network Mgmnt Protocol (SNMP)

Match the well known user datagram protocol (UDP) port numbers with their associated application.

576

On an IP network, all hosts must be able to handle a packet size of at least how many bytes?

Resend segments 3 and 4.

The destination transmission control protocol (TCP) process has set a 1,000-byte receive buffer window. The source TCP sequence number starts at 23,100 and sends the following segments, in order: Segment 1-200 bytes; Segment 2-300 bytes; Segment 3-200 bytes; and Segment 4-300 bytes. The last acknowledgment the source received was sequence number 23,600 saying the receive buffer can now hold 800-300 byte streams. The retransmission timer for sequence number 23,600 has expired, so what will the source TCP do next?

The transfer of information across a transmission control protocol/Internet protocol (TCP/IP) network.

The five steps of (1) obtaining logical addresses, (2) obtaining physical addresses, (3) establishing a connection between applications, (4) the transfer of information, and (5) the termination of the connection are necessary to accomplish what?

7,806,006

The local transmission control protocol (TCP) process sends four segments, each 4 bytes long. The first sequence number is 7,806,002. Which is the acknowledgment number the receiving process returned to indicate it received segment one?

Virtual

Transmission control protocol (TCP) establishes which type of circuit between applications?

The sending host looks in its address resolution protocol (ARP) cache for the necessary mapping.

What happens first when an IP host needs to resolve an IP address to a media access control (MAC) address?

It retransmits the outstanding segments.

What happens if the retransmission timer set by the sending transmission control protocol (TCP) times out before it receives an acknowledgment.

The transmitting network device will drop the datagram, and notify the source.

What happens to a datagram marked as "do not fragment" if it must be transmitted across a network segment with a maximum transmission unit field (MTU) smaller than the datagram?

TCP messages are tracked to ensure they are received; UDP messages are sent without tracking.

What is the primary difference between transmission control protocol (TCP) and user datagram protocol (UDP)?

A UDP destination port number.

What provides user datagram protocol (UDP) with the ability to demultiplex data for an application?

Delay, throughput, reliability, and cost (D-T-R-C) bits.

Which IP packet bits does open shortest path first (OSPF) use to provide Type of Service (ToS) routing?

Version

Which IP packet frame field ensures that the gateways handling a datagram agree on the datagram's format?

Reverse address resolution protocol (RARP).

Which IP protocol allows a diskless workstation to contact a server and obtain an IP address?

Fragment Offset.

Which Internet protocol (IP) packet fragmentation header field specifies where the fragment belongs in the original datagram?

The ARP cache

Which address resolution protocol (ARP) feature allows the local host to maintain a mapping of recently discovered IP-to-media access control (MAC) addresses?

IP and port.

Which addresses combine to create a transmission control protocol (TCP) socket?

The TTL specifies the time a datagram is allowed to remain on the network.

Which best describes IP's use of the time-to-live (TTL) field?

UDP uses port numbers to allow multiple applications to communicate simultaneously on the same host.

Which best describes the user datagram protocol (UDP) demultiplexing process?

It is bidirectional, so both ends can control data flow.

Which best describes transmission control protocol's (TCP) use of the Window header field?

UDP servers must listen for service requests on well known ports, or else the transactions may fail.

Which is a true statement concerning user datagram protocol (UDP)?

6

Which is the Internet protocol (IP) header protocol number used to specify that the packet's contents were created with transmission control protocol (TCP)?

Only the target host responds

Which network segment hosts respond to an address resolution protocol (ARP) request?

Destination and source.

Which of the following two ports are contained in the transmission control protocol (TCP) header?

Acknowledgment number.

Which portion of the transmission control protocol (TCP) header specifies the next sequence number the receiver expects from the connection source?

Reverse address resolution protocol (RARP).

Which protocol allows a diskless workstation to contact a server and obtain an Internet protocol (IP) address?

The initiator sends a SYN segment to the target host's transmission control process (TCP) process.

Which statement best describes Handshake #1?

Proxy ARP allows a router to answer an ARP request on behalf of a remote host.

Which statement best describes proxy address resolution protocol (ARP)?

They identify the sequence number of the first data byte in the segment.

Which statement best describes transmission control protocol's (TCP) use of sequence numbers?

Flow control Packet error recovery. Demultiplexing multiple applications.

Which three choices are transmission control protocol (TCP) features? (Choose three.)

Trivial file transfer protocol (TFTP). Simple network management protocol (SNMP). Domain Name System (DNS).

Which three of the following applications utilize user datagram protocol (UDP)? (Choose three.)

Media access control (MAC) address. Adapter address. Hardware address.

Which three of the following terms refer to a physical address? (Choose three.)

ACK control bits Sequence numbers Checksum

Which three parts of the transmission control protocol (TCP) header help the protocol ensure reliable communications between applications? (Choose three.)

Push

Which transmission control protocol (TCP) function forces data delivery before filling the transmit buffer?

SYN

Which transmission control protocol (TCP) header control bit represents that the message is initiating a connection?

Urgent (URG) Push (PSH).

Which two flags can a sending application set to force the transmission control protocol (TCP) process to send data before filling the transmit buffer? (Choose two.)

201.90.35.78 Port 23

Which two of the following are examples of local area network (LAN) logical addresses? (Choose two.)

SYN-ACK

Which type of packet does the receiving transmission control protocol (TCP) send to the source indicating its receipt of the source's SYN packet?

ACK

Which types of transmission control protocol (TCP) segments contain window size advertisements?

161

Which user datagram protocol (UDP) port address do simple network management protocol (SNMP) agents use to send and receive management requests?

Address resolution protocol (ARP).

You know the logical address of an associate's computer on the company's local network and you want to learn the media access control (MAC) address of your associate's computer. Which of the following tools would you use?

By its media access control (MAC) address.

How does a diskless workstation identify itself when requesting an IP address using reverse address resolution protocol (RARP)?

It sends periodic probe segments and waits for an ACK with a nonzero window size.

How does a sending transmission control protocol (TCP) process handle a zero receive window size?

It sends an RST segment when the maximum retry count is exceeded.

How does a transmission control protocol (TCP) process handle a failed connection?

It sets the receive window size with each ACK segment it returns.

How does the transmission control protocol (TCP) receiver control the data flowing from the source?

It carries port numbers in its header, used to logically address a destination application.

How does the user datagram protocol (UDP) support multiple application destinations on the same host?

4

How many fragments will the transmitting device have to create to match the datagram to the segment's 512 maximum transfer unit (MTU) size, having a 1,500-byte datagram, and a 20-byte IP header?

Address resolution protocol (ARP).

In TCP/IP, what does a network host use to find a physical address, given a logical address?

Datagram routing. Time-to-live (TTL). Differentiated Services Code Point (DSCP).

Internet protocol (IP) provides which three of the following services to transmission control protocol (TCP)? (Choose three.)