9/3 Class Flashcards
Chapter 2
we are on it
Read through chapter 4
do it before we go through it next time
TCIP
most data transmitted over a modern networks uses the TCP/IP standards to communicate
has an IP address called a “host”
wired networks
based on IEEE 802.3(“ethernet”)
wireless networks
based on IEEE 802.11
data types are layered
message or data(HTTP, SMTP, etc)
segments(TCP) or Datagrams(UDP)
packets(IP)
frames(ethernet)
Protocol Data Unit (PDU)
used generically is a simple unit, but often used for higher-level layers (above IP)
unicast traffic
traffic sent from one system to another one
one to one traffic
can traverse subnets
multicast traffic
traffic sent from one system to many other systems
broadcast traffic
traffic sent from one system to all other systems on a network
ARP
maps ethernet addresses to IP adresses)
routers and broadcasts
separate subnets
routers don’t pass broadcasts it would overload the internet
network interface cards (NICs) and cables
connect systems
collision domain
only one system can send data at any given time
collisions occur and the protocols force a resend
switches create separate collision domains to minimize collisions
broadcast domain
all devices on a network can receive broadcast traffic
excessive broadcasts slow a network
routers create separate collision and broadcast domains
Hubs (no longer common)
system NICs connect to physical ports there are collisions but they are resent
switches
system NICs connect to physical ports on the Hub via a cable
data sent to one physical port is forwarded to specific physical ports, not all ports(creates isolated collision domains which scales much better)
bridge
four port bridge creating four collision separate domains(rather than hour connected hubs and one collision domain)(scales better)
most often seen in connecting a wireless network
routers
two subnets connected by a router, which “routes” IP packets
1 (Hub)+5(switch) = 6 collision domains
two broadcast domains
many routers
each router separates subnets to prevent traffic
gateway
each system has a preconfigured default router address… otherwise it would never communicate with other systems on other subnets… such as the internet
firewalls
prevents flow of data to specific IP addresses and TCP ports
by default firewalls are very restrictive
network based and/or host based firewalls
media types
twisted pair cables
fiber optic - type of glass
wireless
submarinecablemap.com
shows you where the fiber optic cables go
twisted pair cables
straight cable
crossover cable
use for similar systems
protocols
provide rules for communication
based on standards issued by standards organization
must be configured properly to keep data flowing
TCP/IP protocol suite
primary networking protocol in use today
services
software applications running on a windows server
intranet
protection from the internet
perimeter network
between internet and intranet to isolate subnets/systems
DMZ - demilitarized zone
extranet
for connecting semi trusted networks, typically business partners
across the internet via WAN connections
OSI model
7 Application - SMB, SMTP, etc
6 Presentation
5 Session - establishes, maintains, and terminates lasting connections between two systems
4 Transport - handles flow control, reliability, and error checking of data traveling on this layer, ports are here
3 Network - packets
2 Data Link - handles data delivery on the LAN moving in frames
1 Physical Layer - physical media, encoding signals, ethernet, typical devices
Please do
