IT420

Data link layer protocols

Ethernet and WiFi

Network layer protocols

IPv4, IPv6, and routing protocols

What is the ARP process

It broadcasts a request packet to all the machines on the LAN and asks if any of the machines are using that particular IP address.

What is the process of dividing a large data stream into smaller pieces prior to transmission?

Segmentation

What is the Sequencing function in network communication

The process of numbering the segments so that the message may be reassembled at the destination.

What is the function of the Address Resolution Protocol

To resolve addresses by finding the MAC address that corresponds to an IP address.

Purpose of the native VLAN

To serve it as a common identifier on opposing ends of a trunk link

Modern Ethernet uses what cabling?

Unshielded twisted pair(UTP/STP) or fiber.

Listening State

Where the designated port goes next in the process. This state determines if the port should continue on to the next stage or not.

How do collisions occur on a network

when two devices attempt to transmit data on a shared circuit. In a shared circuit where multiple devices are listening, only a single device can transmit data at a single point in time which requires the rest of the devices to be listening to the transmission.

What is needed to allow inter-vlan communication?

A router or switch on the 3rd layer would be needed to allow traffic between VLANs.

What is WLAN Security

A security system designed to protect networks from the security breaches to which wireless transmissions are susceptible.

What are the Stub network characteristics

One LAN that never carries multiple router data packets. Data traffic is always to or from local hosts. Has only one entry point and exit point.

What is the Data Link Layer (Network Interface Layer)

Provides communication using node-to-node transformation of the data packets.

Coaxial

Uses electrical signals to transport data through a solid copper core that is surrounded by a braided, outer jacket.

What are the components of a message timing

+ Flow control + Response timeout + Access method

Parts of an IPv4 address

+ Network ID + Host ID

WiFi Authentication method specifics

+ Open authentication. + Shared authentication. + EAP (Extensible Authentication Protocol) authentication

What is the Network Layer (Internet Layer)

+ Provides communication using host-to-host transformation of the data packets. + Units are called frames

As a message moves downward from the application layer to the network interface layer in the sender, headers are ______ .

Added

What is the Encapsulation process

As information is passed down the layers, each layer adds extra information that it needs to deliver the message in a header (sometimes called a trailer).

What are Routing protocol capabilities

Can identify multiple paths to a destination network but needs to have the ability to work out which is the most efficient.

What are three media types found at the Physical layer?

Copper straight-through, fiber optic, and coaxial

Which of the following modulation techniques spreads a signal over a larger frequency band?

DSSS

Which protocol stack layer encapsulates data into frames?

Data link

What is the purpose of the Data Link Layer

Describes methods for exchanging data frames over a common media and detecting and correcting possible errors on the physical layer.

What is the NAT overload process

Designed to map multiple private IP addresses to a single public IP address (many-to-one) by using different ports.

Access method

Determines when someone can send a message.

What is the name of the process of adding protocol information to data as it moves down the protocol stack?

Encapsulation

Describe how a newly connected switch build its MAC address table

It automatically learns the location of the computers that are connected to it based on where a frame comes from on the network.

Response timeout

Manages how long a device waits when it does not hear a reply from its destination.

Flow control

Manages the rate of data transmission and defines how much information can be sent and the speed at which it can be delivered.

What are the primary functions of a router

Managing traffic between these networks by forwarding data packets to their intended IP addresses, and allowing multiple devices to use the same Internet connection.

Which of the following modulation techniques is used in the new 802.11ax standard?

OFDMA

What is the purpose of the Transport layer

Provides communication using process-to-process transformation of the data packets.

When would you enable the Spanning Tree Protocol on a LAN? Why?

STP is used to prevent broadcast storms and layer 2 loops. It prevents loops from being created when there are redundant paths in the network that could potentially slow the network down or cause it to fail.

Fiber optic

Uses bursts of light to transmit data through a glass or plastic core surrounded by a cladding, to keep the light from escaping.

Twisted pair(UTP/STP)

Uses electrical signals to transmit data through two copper wires twisted around each other

Can you have broadcasts at the Layer 2 level? If so, what would the MAC address be?

Yes, you can have broadcasts on layer 2 because it is the data link layer and that is where connections between hosts via MAC address happen. The default MAC address would be "FF-FF-FF-FF-FF-FF".

Two main functions of a Router

1. Determine the best path to forward packets based on the information in its routing table, and... 2. Forward packets toward their destination.

Explain the Client-Server model

A structure where it partitions and distributes the workload between the client and server. The client requests data from the server and the server responds by sending packets of data back to the client. The client can either request or send data based on whether the proper software has been installed.

VLAN advantages

Ease of administration, confinement of broadcast domains, reduced network traffic, and enforcement of security policies.

Which of the following modulation techniques rapidly switches a signal among frequency channels?

FHSS

Parts of the Data-Link frame

Frame header, payload, trailer

Data link layer address

Header contains source and destination IP addresses

Network layer address

Header contains source and destination MAC addresses

What is the purpose of the subnet mask

Helps determine the parts of an IPv4 address by dividing the parts into the network ID and host ID portions. This is then used to determine how many devices can connect to the network.

NAT for security.

Security includes Boundary Reinforcement, the private IP addresses used inside the corporate LAN are not routable from outside.

What is the PDU associated with the transport layer?

Segment

What is the Router forwarding process

Step 1: Send packet to router. Computers send the first packet to the nearest router. Step 2: Router receives packet. Step 3: Router forwards packet. Step 4: Final router forwards message.

Transport layer protocols

TCP and UDP

The role of Administrative Distance and cost in routing

The first criterion that a router uses to determine which routing protocol to use if two protocols provide route information for the same destination.

What is the importance of a Default Gateway

The path used to pass information when the device doesn't know where the destination is.

What is Data Segmentation

The process of breaking up data into smaller units in order to increase speed and efficiency of data transmission.

Which layer is responsible for host-to-host communication?

Transport

Which layer uses protocol ports in the header?

Transport

(T or F) Are broadcasts (unicast, multicast, broadcast) used only in IPv4 networks but not for IPv6?

True

Blocking State

Where the designated port is received to have its frames discarded and sent to the next stage

Forwarding State

Where the port goes in the final stage of the process. The port is allowed to transmit data and begins to forward ethernet frame traffic.

Learning State

Where the port goes next after being "green-lighted" by the Listening State. The interface processes Ethernet frames from the source MAC address.

If the unit exchanged at the internet layer (layer 3) is called a packet and the unit exchanged at the network interface layer (layer 2) is called a frame,

frames encapsulate packets

What is the difference between dynamic and static NAT

static NAT allows a remote host to initiate a connection to a translated host if an access list exists that allows it, while dynamic NAT does not.