D315 MEGA SET

TCP/IP and OSI models

a set of procedures that sends data from one host to another

The 4 layers of TCP/IP model

Network Interface, Network, Transport, Application (no new tasty apples)

The 7 layers of the OSI model

Physical, Data Link, Network, Transport, Session, Presentation, Application (Please do not try stealing pink apples)

layer 1 of TCP/IP model

Network Interface

layer 2 of TCP/IP model

Network

layer 3 of TCP/IP model

Transport

layer 4 of TCP/IP model

Application

Layer 1 of OSI model

Physical

Layer 2 of OSI model

Data Link

Layer 3 of OSI model

Network

Layer 4 of OSI model

Transport

Layer 5 of OSI model

Session

Layer 6 of OSI model

Presentation

Layer 7 of OSI model

Application

Application layer (TCP/IP)

Deals with all information between nodes: HTTP, SSH, NTP

Transport Layer (TCP/IP)

Responsible for end-to-end transport. TCP & UDP live here

Network Layer (TCP/IP)

Defines transmission protocols for the whole network. IP & ICMP live here

Network Interface Layer (TCP/IP)

Establishes how data should be sent through through the network

Where do the transmission control protocol and user datagram protocol live?

Transport Layer (TCP/IP)

Where do the Internet protocol and internet control message protocol live?

Network Layer (TCP/IP)

Physical Layer (OSI)

Responsible for physical connections of devices in the network

Data Link Layer (OSI)

responsible for the error-free delivery of data to node

Network Layer (OSI)

responsible fro transmission of data between hosts in different networks and routing packets

Transport Layer (OSI)

provides services to the application layer and receives services from the network layer. Responsible for the reliable delivery of data to receiving node. Also responsible for retries of data that is lost or corrupted

Session Layer (OSI)

responsible for connection establishment, session maintenance and authentication

Presentation Layer (OSI)

responsible for translating data from application into required format and encrypts data

Application Layer (OSI)

responsible for network applications and their production of data to be trasferred

What does the physical layer contain in the OSI model

hubs, repeaters, modems, and physical cabling

What does the data link layer contain in the OSI model

switches, bridges and wireless/wired network cards

What does the network layer contain in the OSI model

routers

What is the heart of the OSI model

transport layer

What is a firewall

a tool that can help prevent malicious attacks

which layer(s) of the osi model can you find firewalls

data link, network, transport, session and application layers(sometimes presentation layer)

what does a firewall do at the network and data link layer

defines what traffic should go between two networks

what does a firewall do at the transport layer

allow/block traffic from a ports or IP addresses

what is the firewall between the network and transport layer of the osi model called

layer 4 firewall

what is the firewall between the application, presentation, and session layer of the osi model called

layer 7 firewall

what is the layer 7 firewall smart enough to do

decrypt and analyze content going through it

Firewalls can be software devices and hardware devices

true

what does the cost of a firewall depend on

features, capabilities, speed

modem

sends and receives data over analog lines like phone or cable lines

router

point of connection between 2+ networks that forwards data packers

network switch

connects devices in a specific network and allows them to communicate efficiently within the network

bridge

connects 2+ networks and analyzes data packets to determine where to send the packet

repeater

strengthens, replicates, and regenerates weakened signals

hub

connects the router to networks and sends data packets to all devices

what layer of the osi model would you find a switch

data link layer or network layer

what layer of the osi model would you find a router

network layer

what layer of the osi model would you find a modem

physical or data link layer

what layer of the osi model would you find a switch

network or data link layer

what layer of the osi model would you find a bridge

data link layer

what layer of the osi model would you find a hub

physical

what is the difference between utp and stp cables

stp cables have extra shielding to prevent leakage of electrical noise from one wire to another

what is the reason for “twisted pairs“

the tighter the twist the lesser the electrical interference between them and the higher the category

utp cables

pairs of wires twisted around each other to protect and cancel out interference from each other and out side sources

what are utp cable types called

cat cables

what is the speed and use of cat 3 cables

10 mbits/s up to 100 meters, commonly used for phone lines

what is the speed and use of cat 4 cables

supports 16mbits/s up to 100 meters, not commonly used

what is the speed and use of cat 5 cables

100 mbits/s up to 100 meters, used in ethernet, superseded by cat5e

what is the speed and use of cat 5e cables

1 gbit/s up to 100 meters, same as cat5 but with double the twisted pairs

what is the speed and use of cat 6 cables

1gbit/s up to 100 meters, 10 gbit/s up to 55 meters, used in ethernet LANs and data centers

what is the speed and use of cat 6e cables

10 gbit/s up to 100 meters, commonly used in wired networks todayz

common connector for utp phone lines

RJ11

common connector for utp ethernet cables

RJ45

coaxial cables

analog cables made of copper but engineered with a metal shield intended to block signal interference

what are coaxial cables commonly used by

cable tv companies

Fiber cables

use glass or plastic threads within cables to transfer the data using light instead of metal and electricity

what are fiber optic cables used for

high bandwidth needs

what are the advantages of fiber optic

transfer data digitally, more reliable, carry more data at once

single mode cables

made up one fiber, can carry higher bandwidth 50x the distance of a multimode cable

multimode cables

wider to carry more light modes , more effective over medium distances, commonly used within a LAN

what is cheaper single or multi mode cables

multimode cables

straight tip connector

fiber optic connector common with multimode fiber in the mid 2000s

lucent connector

supported more ports being used in the same place, most common type of connector used today

crossover cables

connects 2 devices of the same type to each other

patch cable

used to connect a device to a wall outlet

IEEE

Institute of Electrical and Electronics Engineers, responsible for many networking standards

IEEE standard for wireless networks

802.11

IEEE standard for wired networks

802.3

the higher the frequency

the higher the bandwidth and shorter the distance

which 2 frequencies are unregulated

2.4 & 5 ghz

what is the disadvantage of 2.4 & 5 ghz frequencies

other devices may interfere with the signal, slowing down the communication rate

difference between MAC address and IP address

MAC address is a data link layer and an IP address is a network layer address

sudo command

allows users to run commands as an administrator

ifconfig command

shows how interfaces are setup in a machine

route command

defines the paths a data packet takes between networks

ping command

verifies connectivity and latency

nslookup command

resolves a name associated with an IP address

traceroute command

shows the route a packet takes from one machine to another

whois command

shows who owns a domain and more information about the domain

tracepath command

similar to traceroute command but does not require usage of sudo

ipconfig command

provides the ip, subnet mask, and default gateway for each network adapters

dig command

used to query the dns name servers

arp command

displays the ip to physical mac address mappings

netstat commands

displays information about the active ports and their state

scp command

securely copy files between servers using ssh

ftp command

copies a file from one host to another unencrypted

tftp command

transfers a file from client to server or vice versa

finger command

displays information about users on a remote system

nmap command

scans networks to see what hosts and open ports it can find