MIS Exam 2
NO
Are the victim and default router aware that the man in the middle attack is occurring?
Physical and Data Link layers
At what layers do single networks require standards?
YES
Can Ethernet switches implement priority?
just the core. The cladding is what holds that signal withing the cable
Does the signal travel through the optical fiber core, cladding, or both?
voice over IP phones, surveillance cameras, internet access points
For what types of devices is POE Plus sufficient?
4
HOw many pairs are there in a UTP cord?
Hierarchical switch topology
How are switches in an Ethernet LAN organized?
twisted
How are the two wires in each pair organized?
requires authentication before receiving each packet
How can 802.AE defeat man in the middle attacks?
it can create loops within the network
How does Installing backup links bring redundancy?
because if one switch fails there is another path for the data to go through
How does Installing backup links improve reliability?
ARP cache stores the list of IP addresses and the EUI-48 addresses linked to that IP address
How does a host use information in its ARP cache?
Attacker can receive important information without victim realizing it
How does a man in the middle attack benefit the attacker?
When there are more than 2 signals, if a signal is mis-sent it is harder to determine what it was meant to be.
How does error resistance differ in binary and digital signalling?
it requires users to provide their identity before the workgroup switch will pass further trafic
How does the 802.1X address the threat?
it changes the EUI-48 address to the attacker's address. this sends all the information to the attacker's computer first
How does the ARP cache poisoning packet change the ARP cache on a victim host or router? What are the consequences of this change?
ONE
How many possible paths can there be between any two hosts?
8
How many priority levels can Ethernet switches implement?
8
How many wires are there in a UTP cord?
must configure it's equipment to recognize two optional tag fields
If a company wishes to use priority in Ethernet, what fields must it add?
workgroup switch
In 802.1X, what device is the authenticator?
No, because it is time consuming and expensive and the threat is rare
Is 802.AE widely used?
NO
Is POE Plus sufficient for desktop computers and most notebook computers?
If there is a single backup link it is easy multiple back up links increase difficulty
Is it easy or difficult to create backup links effectively with RSTP?
because having staff travel from switch to switch to manage them costs a significant amount of time and money
Manageable switches cost more than dumb switches. Why is using them worthwhile?
Quality
Of what wire characteristic is category a measure?
Ethernet Cables
What are RJ-45 connectors and jacks also called?
light signals that travel through fiber optic cable
What are modes?
1)Switch Cost- minimizes processing power 2)Consistency- keeps credentials consistant 3)Reduced Management Cost- only has to update the credentials at one point 4)Rapid Changes- credentials can be updated within seconds
What are the four benefits of using a central authentication server instead of having the individual authenticators do all the authentication work?
1)divide the 48 bits into twelve 4-bit units 2)convert each nibble into a hexadecimal symbol 3)write the symbols as six pairs with a dash between each pair
What are the steps in converting EUI-48 addresses into hex notation?
LLC subheader and the packet that the frame is delivering
What are two components of the Ethernet data field?
Allows for firms to remotely reconfigure switches
What benefit does strong security bring for manageability?
Simple Network Management Protocol
What communication protocol is used with manageable switches?
the information in its own switching table
What does a switch know?
850 nm because it travels far enough for the average LAN and is less expensive
What dominates in LANs? why?
receiver discards the frame
What happens if the receiver detects an error in a frame?
Only untwisting a pair 1.25 cm
What installation discipline can make terminal crosstalk interference a nonissue?
Power Over Ethernet Plus is an Ethernet switch that can provide both data and electrical power to connect devices
What is POE Plus?
networks that operate on a customer premises.
What is a local area network (LAN)?
When there is a single point of failure and it creates widespread disruption because there is only single paths for data to follow
What is a single point of failure?
different conditions that differentiate input
What is a state?
two signals traveling different distances because one travels straight and the other bounces from side to side
What is model dispersion?
Interference from other wire pairs within a bundle
What is terminal crosstalk interference?
full duplex transmission
What is the ability to transmit in both directions simultaneously called?
UTP is copper wire and Optical fiber is glass tubing. UTP has a distance limit of 100 meter while Optical fiber can carry signals far longer.
What is the advantage of optical fiber over UTP?
parallel transmission carries 4 bits per cycle while serial is only 1 bit per cycle
What is the average parallel transmission compared to serial transmission?
makes the process very fast and simple and inexpensive
What is the benefit of having a single possible path? explain
50 microns
What is the core diameter of multimode fiber?
8 or 9 microns
What is the core diameter of single mode fiber
the distance between successive wave heights, troughs, starts, stops
What is the definition of wavelength
Logical Link Control Layer has functionality that all 802 standards use to interact with the internet layer Media Access Control layer has functionality specific to a particular working group's core operation
What is the difference between LLC layer and MAC layer?
Binary has two states (conditions) which may be two voltage signals or light being turned on and off. Digital signals have few states there can be 32 to 256 states
What is the difference between binary and digital signalling?
workgroup switches connect hosts to the network core switches connect switches to other switches
What is the difference between the two types of Ethernet switches in terms of what they connect?
Access links connect hosts to workgroup switches Trunk lines connect switches to switches
What is the difference between the two types of Ethernet transmission link technologies in terms of what they connect?
802.11 Working Group
What is the name of its committee for developing LAN standards
describes the type of packet contained in the data field
What is the prupose of the LLC subheader?
permits error detection
What is the purpose of the Frame Check Sequence Field?
Installing backup links
What is the traditional way to address this problem?
25 watts of power
What maximum standard power does the POEplus standard specify?
convert the 1s and 0s into physical signals.
What must a sender do to send the bits of a frame over a transmission medium?
RSTP Standard
What standard allows backup links for redundancy in Ethernet network?
IEEE Standards Association
What standards association creates the most LAN standards?
Connectors, Transmission media, signaling
What three things do physical layer standards govern?
850 nm 1,310nm 1,550nm
What three wavelengths are used in optical fiber transmission?
RJ-45 jack
What type of connectors and jacks does 4-pair UTP use?
UTP cord
What type of copper wiring is widely used in Ethernet?
1000Base-T
What types of UTP wiring can carry signals 100 meters at 1 Gbps
Category 6
What types of UTP wiring can carry signals in 10GBASE-T?
just before the length field
Where are tag fields located if they are present?
802.3 Working Group
Which 802 working group creates ethernet standards?
Category 6A
Which can carry 10 Gbps Ethernet 100 meters?
802.1 Working Group
Which group develops security standards?
in order to differentiate when a new signal starts. for example if you want to signal 1111 you would use 4 clock signals so that the receiver knows that there is four different 1s instead of just one
Why are clock cycles necessary?
because there are multiple paths it can send data on it must take the time to decide the best possible route. This requires more data processing power and therefore costs more.
Why are routers expensive for the traffic volume they handle
because they are hosting many computers while workgroup switches are connecting one computer to the network
Why do core switches need more processing power than workgroup switches?
because it is less expensive and gets the job done
Why does multimode fiber dominate in ethernet LANS anyway?
to have the ability to transmit in two directions at the same time
Why does optical fiber cord have two strands?
Because it is inexpensive to have the fast transmission of data
Why has Ethernet become the dominant LAN technology?
it costs money to run electrical outlets to all the security and access point areas so being able to get power through Ethernet cable is beneficial and cost efficient
Why is POE Plus attractive to corporations
because there are two signals, even if the signal is changed slightly you can still tell which one is was supposed to be. If there are more than 2 it starts to become difficult to determine.
Why is binary transmission error-resistant?
Because if one part fail then it will cause widespread disruption in the system
Why is having a single possible path between any two hosts in an Ethernet network dangerous?
NO
do switches know the entire data link between the source and the destination host?
using two or more UTP or fiber trunk lines to connect a pair of switches
link aggregation
faster links are expensive
why may link aggregation be better than installing a faster link?
because it will slow down the internet considerably
why may link aggregation not be desirable if you will need several aggregated links to meet capacity requirements?
