Module One Assignments

OSI and TCP Layered Models

Application Protocols and DNS

RS Web Hosting

Network Media

Application Protocols and DNS

Application Protocol Questions:

  1. How does the Application level of the TCP/IP model map to the ISO/OSI model?

    2. The application layer of the TCP/IP model contains the application, presentation, and session layers of the OSI model.

  2. The primary difference between FTP and TFTP is user authentication. What is meant by the term "user authentication?"

    3. FTP authenticates with a username and password, whereas TFTP does not require authentication. User authentication means that a user must have the appropriate credentials in order to access and/or edit the file system.

  3. Which protocol is used most often for sending mail between mail servers?

    4. SMTP - Simple Mail Transfer Protocol.

  4. Which mail protocol would you use for receiving mail?

    5. POP3 - Post Office Protocol version 3, which is designed for more intermittent connectivity. IMAP4, Internet Message Access Protocol v4, can also be used for this, is more flexible, and keeps state.

  5. If you are using a conventional browser to surf the Internet, what protocol(s) are you most likely using?

    6. HTTP - Hypertext Transfer Protocol, or HTTPS - Hypertext Transfer Protocol Secure, which uses an extra layer of encryption through TLS/SSL.

  6. If you are buying a product on Amazon or checking your bank balance online, what protocol should you be using?

    7. HTTPS should be used, as it is the encrypted and thus more secure protocol.

  7. Who created SSL?

    8. Netscape

  8. What is TLS? Who created it?

    9. TLS is Transport Layer Security, which is the updated version of SSL (Secure Sockets Layer), and is a protocol for encryption used by HTTPS. IETF created TLS when they updated SSL.

  9. Name common Voice over IP (VoIP) protocols.

    10. SIP - Session Initiation Protocol, responsible for building and tearing down calls. Another is RTP - Real-Time Transport Protocol, which actually carries the media stream.

  10. Which protocol actually sends your voice across the network?

    11. RTP - Real-Time Transport Protocol

DNS Protocol Questions

  1. What is the difference between a routable and a non-routable protocol?

    2. A routable protocol allows the forwarding of data from one network to another network, while a nonroutable protocol cannot be used to route the data over the network. The nonroutable protocol has no network address, only device addresses.

  2. To connect separate routable networks, what hardware device would be appropriate?

    3. A network switch can be used to connect separate networks.

  3. In TCP/IP, what physical device is called the default gateway?

    4. A router is the default gateway in TCP/IP.

  4. What is DNS?

    5. A process that allows you to type in the name of a server, and have that server name automatically resolve to an IP address via the Domain Name System (DNS). It is a hierarchical, distributed database system.

  5. Briefly describe the DNS query/response process.

    6. Resolver software runs on your computer, which takes the domain name and requests for the IP address associate with that domain name. It will first look on your local computer for a host file to attempt to resolve the request, however if it is not there, then it will send a request to local name server to find IP address. If anyone had made a request to that site previously, it may be cached on local name server, and the local name server will give the IP address associated with the domain name. If nothing is cached, the local name server will contact one of the root servers to find out how to resolve the domain name. The root server will instruct which server to contact, for example the .com name server, which will then give the IP address for the name server containing the website. That name server will give the IP address associated with the domain name, which will then be sent to the local name server, cached, and sent back to the user's computer.

  6. What is DHCP (Dynamic Host Configuration Protocol)?

    7. DHCP is an automated way to distribute and update IP addresses and other confiuration informatino on a network. A DHCP server provides this information to a DHCP client through an exchange of messages.

  7. Briefly describe the DHCP process.

    8. There are four steps in the DHCP process. First, the client requests for a DHCP server (DHCPSDISCOVER). Then, the server on the network offers an address to the client (DHCPOFFER). Third, the client broadcasts a request to lease an address from one of the offering DHCP servers (DHCPREQUEST), and finally, the DHCP server that the client responds to acknolwedges the client, assigns it any configured DHCP options, and updates the DHCP database. The client then initializes and binds its TCP/IP protocol stack and can begin network communication.