Chapter 2 - Ethernet Networking and Data Encapsulation Flashcards
Define Ethernet
A contention based, media access method that allows host to share the same links and bandwidth
Define Collision Domain
Every device on the segment must process a frame that is sent out. When there is a collision devices must retransmit. Each port on a switch is considered to be a separate collision domain.
Define Broadcast Domain
A group of devices that hear all broadcasts sent on the network. Can also refer to a logical segment where devices communicate via a data link
What is CSMA/CD
Carrier Sense Multiple Access helps devices share bandwidth while preventing devices from transmitting simultaneously. First it checks the wire and continues to monitor. A jam signal is sent out if another precense is detected.
What is Half Duplex
Using CSMA/CD a signal is trasmitted using a one wire pair running in both directions
What is Full Duplex
Uses a four wire pair running in both directions simultaneously. Collisions do not happen.
Outline the formula for a MAC address
First 24 bits = Organization Unique Identifier Last 24 bits = Vendor Assigned Bit # 47 = Individual/Group Bit - 0 = MAC Address - 1 = Multicast address Bit # 46 = Global/local bit or Universal/Local bit - 0 is globally administered by IEEE - 1 is locally governed and administered
Convert 10000000 to Decimal
128
Convert 11000000 to decimal
192
Convert 11100000 to decimal
224
Convert 11110000 to decimal
240
Convert 11111000 to decimal
248
Convert 11111100 to decimal
252
Convert 11111110 to decimal
254
Convert 11111111 to decimal
255
What is the name for a single hex character
nibble
What is the name for two character hex
byte
Convert 0x6A to Decimal
6 = 0110 & A = 1010
= 01101010
= 128 + 64 + 8 + 4
What is ‘A’ in binary
1010
What is ‘B’ in binary
1011
What is ‘C’ in binary
1100
What is ‘D’ in binary
1101
What is 9 in binary
1001
What is an ethernet frame use for
To encapsulate packets passed down from the network layer from some kind of media access
Outline the Structure of a frame
Preamble | SFD | Destination | Source |Type | Data & Pad | FCS
What is a preamble
Alternating 0 & 1 provides a 5 MHz clock lock on to the data stream
What is a start frame delimeter
Preabmle is 7 octets and the SFD is 1 octet. This allows devices to come into the middle of the preamble and still be able to sync up to the beginning.
Outline 10BaseTX
802.3
Uses CAT3 up to 100m
Devices must connect to a hub or switch
Physical Star or Logical bus topology
Outline 100BaseTX
802.3U
CAT5 up to 100m
Two pair wiring
Physical Star or Logical bus topology
Outline 100Base-FX
802.3U
Fiber Cabling - 62.5/125 micron MMF
412 m max
Uses ST/SC Connectors
Outline 1000Base-CX
802.3z
Copper Twisted Pair
25m max
Uses special 9 pin connector
Outline 1000Base-T
802.3ab CAT5E or higher Uses four pairs (all pairs) 100m max 1 Gbps
Outline 100Base-SX
802.3z
1 Gbps ethernet over MMF using short wave
62.5 @ 220m & 50 Micron @ 550m
Outline 1000Base-LX
802.3z Single mode fiber 9 micron core 1300nm laser 3 km to 20 km
Outline 1000Base-ZX
This is a cisco standard
Single mode fiber over 70 km
Outline 10GBase-T
802.3an
CAT 6 or higher
100m max
What makes the pin out different on a roll over cable
The ends mirror each other
1-8
2-7
…
What makes the pin out different on a crossover cable
T568A on one side and T568B on the other 1 - 3 2 - 6 3 - 1 4 - 7 5 - 8 6 - 2 7 - 4 8 - 5
What is a fiber cable made up of and what are the layers to a fiber cable.
Glass or plastic core. The smaller the core the farther the distance
Cladding wraps around the core to reflect the light
Buffer protects the glass
Sheathing wraps the entire thing
What protocol data unit is used at the network layer
Packets and Datagrams
What protocol data unit is used at the transport layer
Segment
What protocol data unit is used at the data link layer
frames
What protocol data unit is used at the physical layer
bits
What are the steps to processing data from the transmitter
- User info converted to data for transmission on network
- Data converted is segmented and reliable connection is established
- Segments converted to packets/datagrams and logical addressing placed in header
- Packts/datagrams converted to frames and hardware address used to identify hosts
- Frames -> bits, digital encoding/clocking scheme used
What is a socket
a virtual circuit that is the source/destination port plus the source/destination IP address
What are the three layers in the Cisco Hierarchical Model
Core Layer
Distribution Layer
Access Layer
Explain the Core layer in the Cisco Hierarchical Model
- Top
- Responsible for transporting large amounts of traffic reliably & quickly
- Switch Traffic as fast as possible
- Every User loses access when failure
- No access lists, no vlans, no packet filtering
- Avoid expanding - Upgrades before expansion
- Design for reliability
- Design for speed
Select routing protocols with low convergence times
Explain the Distribution layer in the Cisco Hierarchical Model
Workgroup layer
provide filtering, routing, and WAN access
Implement policies here
Redistributing between routing protocols
routing between VLAN
Defines multicast & broadcast domains
Explain the access layer in the Cisco Hierarchical Model
Desktop layer Continues use of access creates separate collision domains device connectivity resiliance and security services advance technology capabilities
