لخّصلي

• Point to Point & Shared Media
• Point to Point (P2P): directly connected, nothing in the way
• Shared Media: Broadcast, a layer 2 device in the way
• Power over Ethernet (PoE):
• Carrying Power over 2 pairs of Copper Cables (enough to power up some network devices)
• Can replace an AC adapter
• PoE Terms: PSE:
• Power Sourcing Equipment (Switches, Power Injectors)
• PD: Powered Device (PCs, IP Phones, IP Cameras)
• Negotiation happens between the PSE & PD before/after starting Suppling
• Power Suppling over PoE can be from 15 - 95 Watts (Total)
• UPoE+: Universal PoE make use of all the 4pair to carry both Data&Power Cisco Certified Network Associate (200-301 CCNA) 20 1.5 Interfaces and Cables Issues:
• Collisions: more than one device (PC) transmitting at a single time in a shared media
• Carrier sense multiple access/collision detection, CSMA/CD Solved it!!- Errors: Cabling Issue, Unsupported SFP
• Duplex Mismatch: Half or Full?MUST MATCH
• Speed: 10/100/1000?

• Point to Point & Shared Media


• Point to Point (P2P): directly connected, nothing in the way


• Shared Media: Broadcast, a layer 2 device in the way


• Power over Ethernet (PoE):


• Carrying Power over 2 pairs of Copper Cables (enough to power up some
  network devices)


• Can replace an AC adapter


• PoE Terms: PSE:


• Power Sourcing Equipment (Switches, Power Injectors)


• PD: Powered Device (PCs, IP Phones, IP Cameras)


• Negotiation happens between the PSE & PD before/after starting Suppling


• Power Suppling over PoE can be from 15 – 95 Watts (Total)


• UPoE+: Universal PoE make use of all the 4pair to carry both Data&Power
  Cisco Certified Network Associate (200-301 CCNA)
  20
  1.5 Interfaces and Cables Issues:


• Collisions: more than one device (PC) transmitting at a single time in a
  shared media


• Carrier sense multiple access/collision detection,
  CSMA/CD Solved it!!


• Errors: Cabling Issue, Unsupported SFP


• Duplex Mismatch: Half or Full? MUST MATCH


• Speed: 10/100/1000? MUST MATCH
  Cisco Certified Network Associate (200-301 CCNA)
  21
  1.6 Networking Languages:
  A – The Binary Language:


• Only 2 digits: 0 & 1


• Everything is Binary


• Each digit = 1 bit


• Zeros are low Electric pulse, low frequency light wave,
  Once are the opposite
  B – The Decimal Language:


• 10 digits: 0 – 9


• Value: 0 – 255


• NO Number “10”


• For humans, ease
  C - The Hexa-Decimal Language:


• 16 digit: 0 – 9, A – F


• 0 = smallest value, F = biggest value
  Cisco Certified Network Associate (200-301 CCNA)
  22
  1.7 Media Access Control Address (MAC Address):


• Layer 2 Technology


• Hexa-Decimal Language


• Physical Address


• Constant and Unique


• 48 Bit length


• Half for the Organization, half for the product
  Cisco Certified Network Associate (200-301 CCNA)
  23
  1.8 Internet Protocol Version 4 (IPv4):


• Layer 3 Technology


• Decimal Language (and Binary)


• Logical Address


• Variable, based on the need


• 32 Bit length


• Part for the Network, Part for the Hosts


• 4 Octets, each =?


• Addressing:


• convert from binary to decimal, and vice versa


• What defines network octets from hosts octets?


• Total Hosts = 𝟐𝟑𝟐 = 4,294,967,296

Cisco Certified Network Associat