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25 Cards in this Set
- Front
- Back
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What does a repeater do?
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Takes an incoming signal and then generates a new, clean copy of that exact signal. This prevented maximum cable lengths from stopping transmissions, and also helped to ward off attenuation.
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How is a hub different from a repeater?
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It is basically the same except that the hubs will have more ports.
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What layer of the OSI model do hubs run?
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Physical layer
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How does CSMA/CD (Carrier Sense Multiple Access with Collision Detection) work?
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A host will first listen to the wire. If the media is in use, the hose backs off for a few milliseconds before checking again. If it is not in use, the host sends the data.
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What is a data collision?
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When two PCS send data at the exact same time. When this happens, the PCs generate a jam signal, and the voltage on the wire changes.
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What is the term microsegmentation?
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Used to describe "one host, one collision domain".
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What are the three actions a Cisco switch can take with an incoming frame?
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Forward, Flood, or Filter
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Who receives a flood packet on a switch?
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It is broadcast to every port on the switch except for the port that it originated on.
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When will a switch flood a frame?
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Flooding is performed when the switch has no entry for the frame's destination MAC address. When a frame is flooded, it is sent out on every single port on the switch except the one that it came in on.
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When will a switch forward a frame?
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Forwarding is performed when the switch does have an entry for the frame's destination MAC address. Forwarding means the frame is being sent out only one port of the switch.
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When will a switch filter a frame?
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Filtering is performed when the switch has an entry for both the source and destination MAC address, and the MAC table indicates that both addresses are found off the same port.
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What type of frame is sent to all hosts?
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Broadcast frames sent to FF-FF-FF-FF-FF-FF
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What are the different names for a MAC table?
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CAM table, Bridging table, Switching table, MAC table
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Once the switch decides whether to forward, filter, or flood the frame, there's one more decision that needs to be made. What are the 3 processing methods to handle the forwarding?
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Store and forward, Cut through, and Fragment-free
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What is a broadcast storm?
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The continual generation of new broadcasts. A broadcast storm can overwhelm a switch's memory and CPU.
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What is a campus LAN?
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Term used to describe any network that connects multiple buildings that are physically close to each other.
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What is STP (Spanning Tree Protocol)?
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Used to prevent switching loops. STP will determine a loop-free path for frames, and ports that are not on that path will be placed into blocking mode.
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What can you do to increase security on a Cisco switch?
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Close unused ports with the shutdown command.
Prevent the port from trunking with the switchport command. Place the port into an unused VLAN. |
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What is the command that allows you to specify a secure mac address?
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mac-address
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What is the command that allows you to specify what should happen if a non-secure source MAC address is received on the port?
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violation
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What will the interface status look like if a port has been shut down due to an invalid MAC address?
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err-disabled
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What are the commands to shut down a port if a frame is received with any source MAC address other than bb-bb-bb-bb-bb-bb?
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int fast 0/3
switchport mode access switchport port-security switchport port-security mac-address bbbb.bbbb.bbbb |
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What command do you use if you don't know the allowed MAC address, and would like the switch to only allow the first MAC address that it sees?
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switchport port-security mac-address sticky
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What command do you run to verify that port security is running?
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show port-security interface fast0/3
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What is the command to open a port that has been previously shut down?
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no shutdown
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