Explain back-off-timer and what methodology is it used in.
Back-off-timer is the technology used when a network device notices a collision of its data on the wire, it is the time waited to retransmit its data.
What is the name of the procedure utilitizing back-off-timer methodology?
Carrier Sense Multiple Access/Collision Detection (CSMA/CD)
Explain the break down of CSMA/CD
Carrier Sense is the devices method of listening on the wire to ensure no data frames are being transmitted.
Multiple Access is the philosophy that all eligible devices have simultaneous access the network segment.
Collision Detection is
when a network device notices a collision of its data on the wire, it is the time waited to retransmit its data.
What is said to be a collision domain?
All devices on a share ethernet segment.
What improved the scalability of ethernet networks?
Ethernet switches by creating multiple collision domains because each port on an ethernet switch is its own collision domain.
Identify the distance limitation of a 10BASE5 Ethernet network.
A. 500 m
If two devices simultaneously transmit data on an Ethernet network and a collision occurs, what does each station do in an attempt to resend the data and avoid another collision?
A. Each device sets a random back off timer, and the device will attempt retransmission after the timer expires.
What kind of media is used by 100GBASE-SR10 Ethernet?
A. MMF
Which of the following statements are true regarding VLANs? (Choose two.)
a. A VLAN has a single broadcast domain.
b. For traffic to pass between two VLANs, that traffic must be routed.
c. Because of a switch’s MAC address table, traffic does not need to be routed to pass between two VLANs.
d. A VLAN has a single collision domain.
a. A VLAN has a single broadcast domain.
b. For traffic to pass between two VLANs, that traffic must be routed.
What name is given to a VLAN on an IEEE 802.1Q trunk whose frames are not tagged?
A. Native VLAN
In a topology running STP, every network segment has a single ______________ port, which is the port on that segment that is closest to the root bridge, in terms of cost.
B. Designated
What is the IEEE standard for link aggregation?
B. 802.3ad
What is the maximum amount of power a switch is allowed to provide per port according to the IEEE 802.3af standard?
C. 15.4 W
What switch feature allows you to connect a network sniffer to a switch port and tells the switch to send a copy of frames seen on one port out the port to which your network sniffer is connected?
B. Port mirroring
Which IEEE 802.1X component checks the credentials of a device wanting to gain access to the network?
C. Authentication server
What was the original intent of ethernet created by Xerox?
To connect computers to laser printers.
Explain the components of 10Base5.
The 10 in 10BASE5 referred to network throughput, specifically 10 Mbps (that is, 10 million (mega) bits per second). The BASE in 10BASE5 referred to baseband, as opposed to broadband
What is the bandwidth, media type and distance limitation of 10Base5.
10Mbps, Coaxial (Thicknet), 500m
What is the bandwidth, media type and distance limitation of 10Base2
10Mbps, Coaxial (Thinnet), 185m
What is the bandwidth, media type and distance limitation of 10BaseT
10Mbps, Cat3 (UTP), 100m
What is the bandwidth, media type and distance limitation of 10BaseTX
100Mbps, Cat5 (UTP), 100m
What is the bandwidth, media type and distance limitation of 10BaseFX
100Mbps, MMF, 2km
What is the bandwidth, media type and distance limitation of 1000BaseT
1Gbps, Cat5e (UTP), 100m
What is the bandwidth, media type and distance limitation of 1000BaseTX
1Gbps, Cat6 (UTP), 100m
What is the bandwidth, media type and distance limitation of 1000BaseLX
1Gbps, MMF/SMF, 5km
What is the bandwidth, media type and distance limitation of 1000BaseLH
1Gbps, SMF, 10km
What is the bandwidth, media type and distance limitation of 1000BaseZX
1Gbps, SMF, 70km
What is the bandwidth, media type and distance limitation of 10GBaseSR
10Gbps, MMF, 26-82km
What is the bandwidth, media type and distance limitation of 10GBaseLR
10Gbps, SMF, 10km
What is the bandwidth, media type and distance limitation of 10GBaseER
10Gbps, SMF, 40km
What is the bandwidth, media type and distance limitation of 10GBaseSW
10Gbps, MMF, 300m
What is the bandwidth, media type and distance limitation of 10GBaseLW
10Gbps, SMF, 10km
What is the bandwidth, media type and distance limitation of 10GBaseEW
10Gbps, SMF, 40km
What is the bandwidth, media type and distance limitation of 10GBaseT
10Gbps, Cat6a, 100m
What is the bandwidth, media type and distance limitation of 100GBaseSR10
100Gbps, MMF, 125m
What is the bandwidth, media type and distance limitation of 100GBaseLR4
100Gbps, SMF, 10km
What is the bandwidth, media type and distance limitation of 100GBaseER4
100Gbps, SMF, 40km
On a basic switch configuration, all ports on a switch belong to what?
Broadcast domain
What is the most popular IEEE trunking standard?
IEEE 802.1Q
How are other VLANs differentiated from the Native VLAN?
They are tagged
How do layer 3 packets differ from layer 2 frames?
layer 2 frames do not have Time-to-live TTL
What is IEEE 802.1D?
Spanning Tree Protocol (STP), allows networks to layer 2 loops whiles not allowing them to spill over to other ports.
The IEEE standard that allows a maximum of 15.4 watts of power is what?
IEEE 803.af
What IEEE standard affords 32.4 watts of power and enable PoE?
IEEE 802.3at
What standard enforces user authentication?
IEEE 802.1X
A device that wants to gain access to a network is called what?
Supplicant
What forwards the supplicant's request to the authentication server?
Authenticator
What does the authenticator do after the authentication server grants access?
It receives a key and establishes a secure session with the supplicant.
What name is given to a VLAN on an IEEE 802.1Q trunk whose frames are not tagged?
A. Native VLAN
What is IEEE 802.3 standard?
Ethernet - developed by Xerox in 1973 as a solution to communicate with printers.
The first iteration of Ethernet was 10Base5,
explain what this means?
10 represents the throughput, 10Mbps.
Base represent Baseband.
5 represents the distance limitation 5 meters.
What was 10Base5 also called?
Thicknet
Explain 10Base2.
Also called thinnet or cheapernet.
The 2 represents the 2meter limitation, which is actually 185meters.
Explain the bandwidth speeds by Ethernet type.
Ethernet - 10Mbps (10 million bits per second)
Fast Ethernet - 100Mbps
Gigabit Ethernet - 1Gbps
10 GB Ethernet - 10 Gbps
100 GB Ethernet - 100 Gbps
What is a GBIC and a SFP?
GigaBit Interface Converter (GBIC)
Small Form-Factor Pluggable (SFP)
Why is 100BaseT and 100BaseTX confusing?
100BaseT is not a specific standard but rather a category of standards. The same is true with 100BaseSE-X
What is a root bridge?
A switch elected to act as a reference point for a spanning tree. The SW with the lowest Bridge ID (BID) is elected root bridge.
What is a nonroot bridge?
All other SW in the STP topology are considered nonroot bridges.
What are the port costs on Long STPs?
2,000,000 for 10Mbps to as little as 2 for 10Tbps.
Which SW will be elected root bridge and why?
SW with MAC address AAAA will be root bridge because port IDs are the same (32768) so the lowest MAC address becomes root.
What are the various port costs for link speeds?
Link Speed STP port cost
10Mbps (Ethernet) 100
100Mbps (Fast Ethernet) 19
1Gbps (Gigabit Ethernet) 4
10Gbps (10-Gigabit Ethernet) 2
What is IEEE 802.1X?
Standards-based method for enforcement of user authentication.
What are the three primary components of an IEEE 802.1X network?
Supplicant - the device requesting access to the network.
Authenticator - That or Who submits the supplicant for authentication.
Authentication server
With 100BaseT, what is the max distance between the hub (or switch) and the node?
B) 100Gbps, SMF, 10km
What type of cable and connector does 100BaseFX use?
A) Multimode fiber with ST or SC connectors
How many pairs of wires do 10BaseT and 100BaseT use?
A) 2
What standard does IEEE 802.3ab describe?
B) 1000BaseT
What is the big physical difference between 1000BaseSX and 100BaseFX
B) 1000BaseSX uses the ST connector exclusively.
What is the max distance for 1000BaseLX without repeaters?
A) 5000 meters
What is the big advantage to using fiber-optic?
D) Fiber is not affected by EMI.
How many wire pairs does 1000BaseT use?
A) 4
What is the standard connector for the 10GbE fiber standard?
B) There is no standard
What is the max cable length of 10GBaseT on CAT6?
A) 55 meters
What is a T-carrier
A) Trunk-carrier or Terrestrial carrier
How many channels are used in a T-1 carrier
A) 24
What is the speed of a T-1 carrier
D) 1.544 Mbps
What carrier uses 32 channels
B) E1
What is the speed used on a E-1 carrier?
B) 2.048 Mbps
What channel and speed is used for a T-3 carrier
672 channels and 44.736 Mbps
How many channels and speed is used for an E-3 carrier
