Index

COMPUTER NETWORKING

  1. INTRO
    1. TCP/IP Five Layer Model
    2. NETWORKING DEVICES
    3. PHYSICAL LAYER
    4. DATALINK LAYER
  2. NETWORK LAYER
    1. IP
    2. SUBNET
    3. ROUTING
  3. TRANSPORT & APPLICATION LAYER
    1. TRANSPORT LAYER
    2. CONTROL FLAGS
    3. APPLICATION LAYER
    4. ALL TOGETHER
  4. NETWORK SERVICES
    1. DNS - NAMES RESOLUTION
    2. DHCP
    3. NAT
    4. VPN
  5. CONNECTING TO INTERNET
    1. BROADBAND
    2. WAN
    3. WIRELESS NETWORKING
  6. TROUBLESHOOTING
  7. MORE ABOUT
    1. DNS
    2. IPv6
    3. CLOUD

NETWORKING DEVICES


Cables

:


Connect different devices, transfer of data. and Fiber.
• Copper : Cat5 , Cat5e , Cat6 -number of twists and other specifics (networking cables). Uses voltage for 1,0
⇒ Cat5 is replaced by Cat5e due to crosstalk. Crosstalk : When an electrical pulse on one wire is detected by another wire.
• Fiber Optics : Individual optical fiber made of glass. Use pulses of light. for 1,0. Less potential data loss.

Hubs

 : (LAN - single network)
A Physical Layer device that allows for connections from many computers at once.
All devices conected to the hub will recieve the data. Whether needed or no. Hence, causes a lot of noise. So, only one device can communicate at a time.
Not much used today.

Switch or Switching Hub

:

 (LAN - single network)
Simillar to the hub but is a layer 2 - datalink layer.
inspect the contents of Ethernet ,sends the data to the exact place. not all.
Eliminates Collision Domains.

Routers

:


Knows how to forward data to computers on other networks
Network layer
Inspects IP data .
Core ISP routers : deals with large network.
BGP(Border Gateway Protocol) : Routers share data with each other via this protocol, which lets them learn about the most optimal paths to forward traffic.
Guides traffic to the right place globally