1. Intro to TCP/IP Networking

What is Layer 7 of the OSI model called?

Application Layer

What is the function of Layer 7 of the OSI Model?

Application Layer, Provides an interface from the the application to the network by supplying a protocol with actions meaningful to the application, for example "get web page object"

What are examples of TCP/IP Application Layer protocols

HTTP, POP, SMTP

What are examples of TCP/IP Internet Layer protocols

IP

What is Layer 1 of the OSI model called?

Physical Layer

What is the function of Layer 1 of the OSI Model?

Physical Layer, defines the physical characteristics of the transmission medium, including connections, pins, use of pins, electrical currents, encoding, light modulation, and so on.

The process of a web server adding a TCP header to the contents of a web page, followed by adding an IP header and then adding a data link header and trailer, is an example of what? a. Data encapsulation b. Same-layer interaction c. OSI model d. All of these answers are correct.

a. Data encapsulation

Which of the following protocols are examples of TCP/ IP data link layer protocols? (Choose two answers.) a. Ethernet b. HTTP c. IP d. UDP e. SMTP f. TCP g. PPP

a. Ethernet g. PPP

Which OSI layer defines the standards for cabling and connectors? a. Layer 1 b. Layer 2 c. Layer 3 d. Layer 4 e. Layer 5, 6, or 7

a. Layer 1

What does TCP use to recover form errors?

acknowledgements

The process of HTTP asking TCP to send some data and making sure that it is received correctly is an example of what? a. Same-layer interaction b. Adjacent-layer interaction c. OSI model d. All of these answers are correct.

b. Adjacent-layer interaction

The process of TCP on one computer marking a TCP segment as segment 1, and the receiving computer then acknowledging the receipt of TCP segment 1 is an example of what? a. Data encapsulation b. Same-layer interaction c. Adjacent-layer interaction d. OSI model e. All of these answers are correct.

b. Same-layer interaction

Which OSI layer defines the functions of logical network-wide addressing and routing? a. Layer 1 b. Layer 2 c. Layer 3 d. Layer 4 e. Layer 5, 6, or 7

c. Layer 3

Which of the following terms is used specifically to identify the entity created when encapsulating data inside data link layer headers and trailers? a. Data b. Chunk c. Segment d. Frame e. Packet

d. Frame

Which of the following protocols are examples of TCP/ IP transport layer protocols? (Choose two answers.) a. Ethernet b. HTTP c. IP d. UDP e. SMTP f. TCP

d. UDP f. TCP

What is a TCP/IP Data Link Layer PDU called?

Frame

What is a TCP/IP Network Layer PDU called?

Packet

What are the Layers of the updated TCP/IP Model

Application Transport Network Data Link Physical

What type of adjacency\interactions is described below?: One a single computer, one layer providers a services to a higher layer. The software or hardware that implements the higher layer requests that the next lower layer perform the needed functions.

Adjacent layer interaction on the same computer

What are the Layers of the original TCP/IP Model

Application Transport Internet Link

Basic Routing Example: Step 1, on the left of Figure 1-10, begins with Larry being ready to send an IP packet. Larry's IP process chooses to send the packet to some router— a nearby router on the same LAN— with the expectation that the router will know how to forward the packet. (This logic is much like you or me sending all our letters by putting them in a nearby mailbox.) Larry doesn't need to know anything more about the topology or the other routers. At Step 2, Router R1 receives the IP packet, and R1' s IP process makes a decision. R1 looks at the destination address (2.2.2.2), compares that address to its known IP routes, and chooses to forward the packet to Router R2. This process of forwarding the IP packet is called IP routing (or simply routing). At Step 3, Router R2 repeats the same kind of logic used by Router R1. R2' s IP process will compare the packet's destination IP address (2.2.2.2) to R2' s known IP routes and make a choice to forward the packet to the right, on to Bob. You will learn IP to more depth than any other protocol while preparing for CCENT and CCNA. Practically half the chapters in this book discuss some feature that relates to addressing, IP routing, and how routers perform routing.

Basic Routing Example

What is Layer 2 of the OSI model called?

Data Link Layer

What is the function of Layer 2 of the OSI Model?

Data Link Layer, Like TCP/IP Data link layer, defines the protocols for delivering data over a particular single type of physical media

What are examples of TCP/IP Link Layer protocols

Ethernet, Point-to-Point (PPP), T1

What is Layer 3 of the OSI model called?

Network Layer

What is the function of Layer 3 of the OSI Model?

Network Layer, Like TCP/IP network layer, defines logical addressing , routing (forwarding), and the routing protocols used to learn routes

What is Layer 6 of the OSI model called?

Presentation Layer

What is the function of Layer 6 of the OSI Model?

Presentation Layer, This layer negotiates data formats, such as ASCII text, or images types like JPEG

What type of adjacency\interactions is described below?: Two computers use a protocol to communicate with the same layer on another computer. The protocol defined by each layer uses a header that is transmitted between the computers to communicate what each wants to do. Header information added by a layer of the sending computer is processed by the same layer of the receiving computer.

Same-layer interaction on different computers

What is a TCP/IP Transport Layer PDU called?

Segment

What is Layer 5 of the OSI model called?

Session Layer

What is the function of Layer 5 of the OSI Model?

Session Layer, provides methods to group multiple bidirectional messages into a workflow for easier manaement and easier backout of work that happened if the entire workflow fails

What is the process by which TCP/IP host send data?

Step 1. Create and encapsulate the application data with any required application layer headers. For example, the HTTP OK message can be returned in an HTTP header, followed by part of the contents of a web page. Step 2. Encapsulate the data supplied by the application layer inside a transport layer header. For end-user applications, a TCP or UDP header is typically used. Step 3. Encapsulate the data supplied by the transport layer inside a network layer (IP) header. IP defines the IP addresses that uniquely identify each computer. Step 4. Encapsulate the data supplied by the network layer inside a data link layer header and trailer. This layer uses both a header and a trailer. Step 5. Transmit the bits. The physical layer encodes a signal onto the medium to transmit the frame.

Describe the how the link layer helps transmit data.

Step 1. Larry encapsulates the IP packet between an Ethernet header and Ethernet trailer, creating an Ethernet frame. Step 2. Larry physically transmits the bits of this Ethernet frame, using electricity flowing over the Ethernet cabling. Step 3. Router R1 physically receives the electrical signal over a cable, and re-creates the same bits by interpreting the meaning of the electrical signals. Step 4. Router R1 de-encapsulates the IP packet from the Ethernet frame by removing and discarding the Ethernet header and trailer. By the end of this process, the link-layer processes on Larry and R1 have worked together to deliver the packet from Larry to Router R1.

What are examples of TCP/IP Transport Layer protocols

TCP, UDP

What is Layer 4 of the OSI model called?

Transport Layer

What is the function of Layer 4 of the OSI Model?

Transport Layer, Much like TCP/IP transport layer, focuses on the data delivery between the two endpoints hosts