7 Ethernet Switching - Quizes

methods of memory buffering

- Port-based memory - Shared memory

forwarding methods for switching data between network ports used by swtiches

- Store-and-forward switching - Cut-through switching

What is a function of the MAC sublayer? (Choose three.)

- controls access to the media - checks for errors in received bits - uses CSMA/CD or CSMA/CA to support Ethernet technology

Which two types of memory buffering techniques are used by switches? (Choose two.)

- port-based memory buffering - shared memory buffering

Which part of an Ethernet Frame uses a pad to increase the frame field to at least 64 bytes?

Data field

Which part of an Ethernet Frame describes the higher-layer protocol that is encapsulated?

EtherType

Which part of an Ethernet frame detects errors in the frame?

Frame Check Sequence

Which data link sublayer controls the network interface through software drivers?

LLC

Which data link sublayer works with the upper layers to add application information for delivery of data to higher level protocols?

LLC

Which part of an Ethernet Frame notifies the receiver to get ready for a new frame?

Preamble

What feature automatically negotiates the best speed and duplex setting between interconnecting devices?

autonegotiation

Which switching method can be implemented using fast-forward switching or fragment-free switching?

cut-through switching

What are two methods for switching data between ports on a switch? (Choose two.)

cut-through switching store-and-forward switching

Cut-through switching

forwards the frame before it is entirely received - two variants of cut-through switching: Fast-forward switching & Fragment-free switching

Fast-forward switching

immediately forwards a packet after reading the destination address

Store-and-forward switching

receives the entire frame and computes the CRC. CRC uses a mathematical formula to determine whether the received frame has an error. CRC is valid => the switch looks up the destination address => the frame is forwarded out of the correct port ADVANTAGE: determines if a frame has errors before propagating the frame

Fragment-free switching

the switch stores the first 64 bytes of the frame before forwarding - compromise between store-and-forward switching and fast-forward switching