Zusammenfassung der Ressource
Chapter 4 - The Current
Ethernet Specification
- Ethernet Basics
- Collision Domain
- Scenario where one device sends a packet on a network segment which forces
every other device on that same physical network segment to pay attention to it.
- Typically found in a hub environment
- Broadcast Domain
- The set of all devices on a
network segment that hear all the
broadcasts sent on that segment.
- Boundary delimited by physical media like switches and
repeaters, reference to logical division where all hosts can
reach each other via a Data Link layer broadcast.
- CSMA/CD
Carrier Sense
Multiple Access
w/ Collision
Detection
- Protocol that helps devices share the bandwidth evenly without having
two devices transmit at the same time on the network medium.
- Check for presence of
signal
- If clear proceed to transmit.
- trnsmit host constantly check
for signal on wire.
- Send Jam to all hosts if
signal detected
- Respond to jam by
waiting random time
before ransmit again.
- If after 15 tries still
collisions the host trying
to transmit will time out
- Half-Duplex
- Using only one wire pair. Either
transmitting or receiving but not both.
- Full-Duplex
- Uses 2 pairs of wires. Can transmit
and receive simultaneously.
- Collision prevention
- 200Mbps - Aggregate rate.
- Ethernet = Connection media-access
method that allows all hosts on a network to
share the same bandwidth of a link.
- Ethernet and the Data Link Layer
- Binary to Decimal
& Hex Conversion
- Nibble - 4 bits
- Nibble Values 8-4-2-1
- Byte - 8 bits
- Byte Values128 -64 -
32 - 16 - 8 -4 - 2 - 1
- Ethernet Addressing
- Mac Address/Hardware Address
- 48 bit - 6 byte
- |-------24bits-----------|------------24bits----------|
IG / GL | OUI | Vendor Assigned
- OUI - Organizationally unique
identifier = Assigned by IEEE to
an organization
- IG = Individual/Group bit =
When 0 assume device, when 1
assume broadcast or multicast
- GL = Global/Local bit = When 0
globally administered address, 1
locally administered.
- Ethernet Frames
- Encapsulate packets handed
down from the Network Layer
for transmission on a type of
physical media
- Channel Bonding
- 2 or more network interfaces on a
host are combined for redundancy
and/or increased throughput
- Ethernet at the Physical Layer
- 10Base2 (IEEE 802.3)
- Coax , 10Mbps, 185 meters
- 10Base5 (IEEE 802.3)
- Coax, 10Mbps, 500 meters
- 10BaseT IEEE (802.3)
- UTP, 10Mbps, 100 meters
- 100BaseTX (IEEE 802.3u)
- UPT - STP, 100Mbps, 100 meters
- 100BaseFX (IEEE 802.3u)
- Fiber, 10Mbps, ~500 to 2,000 meters
- 1000BaseCX (IEEE 802.3z
- Balanced - Shielded Copper, 1000Mbps, 25 meters
- 1000BaseT (IEEE 802.3ab)
- UTP, 1000Mbps, 100 meters
- 1000BaseSX (IEEE 802.3z)
- MMF, 1000Mbps, 550 meters
- 1000BaseLX (IEEE 802.3z)
- MMF - SMF, 1000Mbps, 550 meters MMF/ 2,000 meters SMF
- 10GBaseT (IEEE 802.3an)
- UTP, 10Gbps, 100 meters
- 10GBaseSR
- MMF, 10Gbps, 300 meters
- 10GBaseLR
- SMF, 10Gbps, 10 kilometers
- 10GBaseER
- SMF, 10Gbps, 30 kilometers
- 10GBaseSW
- MMF, 10Gbps, 300 meters
- 10GBase-LW
- SMF, 10Gbps, 10 kilometers
- 10GBaseEW
- SMF, 10Gbps, 40 kilometers