Networking Basics Module 15 – 17 Checkpoint Test Online

Hint

At the transport layer, TCP uses the sequence numbers in the header of each TCP segment to reassemble the segments into the correct order.

Hint

When used by itself (without any options), the netstat command will display all the active TCP connections that are available.

Hint

Because a session does not have to be established for UDP, the client selects a random source port to begin a connection. The random port number selected is inserted into the source port field of the UDP header.

Hint

The TCP protocol works between end devices, not between each device on the network. Routers, switches, etc. do not participate in the packet recovery process. For each TCP segment (or group of segments) sent by a host, there is an acknowledgment. If the sender does not receive an acknowledgment within a period of time, the sender resends the segment.

Hint

The transport layer of the TCP/IP model is responsible for ensuring that all packets in a message are received, reassembling the message in the correct order after all packets are received, and identifying which applications are sending and receiving network data.

Hint

Port numbers are used in TCP and UDP communications to differentiate between the various services running on a device. The well-known port number used by HTTPs is port 443.

Hint

UDP is not a connection-oriented protocol and does not provide retransmission, sequencing, or flow control mechanisms. It provides basic transport layer functions with a much lower overhead than TCP. Lower overhead makes UDP suitable for applications which are sensitive to delay.

Hint

Place the options in the following order:

hosts a web page	web server
requests a web page	web client
used to create web pages	HTML
secure protocol that uses port 443	HTTPS
protocol commonly used by a web browser	HTTP

Hint

URLs are used to access specific content on a web server through a web browser. The URL identifies the protocol that is being used such as HTTP or FTP, the domain of the server, and the location of the resource on the server.

Hint

From the PDU, the destination port is 443, which means the service requested is HTTPS.

Hint

A socket is defined by the combination of an IP address and a port number, and uniquely identifies a particular communication.

Hint

The IMAP4 protocol uses the TCP protocol with port 143 for accessing emails stored on a local server.

Hint

When a client is initiating a request to open an FTP session, it does so by sending a packet to the FTP server with the destination port 21.

Hint

The email protocols used on a network are SMTP, POP3, and IMAP4. SMTP is used to send messages to a local email server, whereas POP and IMAP are used to receive email.

Hint

Place the options in the following order:

Displays the route taken to the destination.	tracert
Directly queries the name server for information on a destination domain.	nslookup
Tests connections to other IP hosts.	ping
Displays network connections.	netstat
Displays IP configuration information.	ipconfig

Hint

Place the options in the following order:

Use the ping command utility for IPv4 only.	ping -4
Use the ping command utility for IPv6 only.	ping -6
Use the ping command utility to resolve the address to the hostname.	ping -a
Use the ping command utility to continue pinging the target interface until manually stopped.	ping -t

Hint

The tracert command sends three pings to each hop (router) in the path toward the destination and displays the domain name and IP address of hops from their responses. Because tracert uses the ping command, the travel time is the same as a standalone ping command. The primary function of a standalone ping command is to test the connectivity between two hosts.

Hint

The ping command is used to verify connectivity to a device,the commands ipconfig /flushdns will cause the adapter to flush the DNS cache, while ipconfig / displaydns will result in the display of the DNS information in the cache.

Hint

The ping command is used to test end-to-end connectivity between the source and destination IP address. It measures the time it takes a test message to make a round trip between the two end points. However, if the message does not reach the destination, or in the case of delays, there is no way to determine where the problem is located.

Hint

Forcing a PC to release its DHCP binding allows a new DHCP request operation to occur. The net, tracert, and nslookup commands do not have any effect on DHCP configurations.