Module 7 - Encapsulation and the Ethernet Frame Flashcards
(20 cards)
Which address is permanently embedded on every Ethernet NIC and used in Ethernet communication?
A MAC Address
Which field in the Ethernet frame helps synchronize the receiving NIC with incoming bits?
Preamble field
Which Ethernet frame field can either specify the payload size or the type of encapsulated data?
The length/type field
Which field in the Ethernet frame is used to verify data integrity after transmission?
FCS (Frame check sequence)
Which field in the Ethernet frame indicates that the actual Ethernet frame data is about to begin?
SFD (Start frame delimiter)
Which part of the Ethernet frame carries the actual payload like IPv4, TCP, or HTTP data?
The Data Field
Which process involves wrapping data inside successive formats for transmission across a network?
Encapsulation
Which Ethernet component is responsible for communicating on a LAN and includes a unique MAC address?
A NIC
Which unit of data includes source and destination addresses before transmission over a network?
A Frame
Which OSI model layer do Ethernet switches operate at when making forwarding decisions?
Layer 2, Data link layer
Which type of information do switches use to decide how to forward Ethernet frames?
Destination MAC address in the internet frame
Which internal data structure do switches use to track device MAC addresses and their corresponding ports?
A MAC address table
What is the first action a switch performs when it receives an Ethernet frame?
Examines source MAC address
What happens if the switch does not find the destination MAC address in its table?
It sends the frame to all ports except the source (unknown unicast)
What does a host do when it receives a frame with a destination MAC address that doesn’t match its own?
It discards the frame
What does the switch do with the source MAC address if it hasn’t seen it before?
It adds it to the MAC Address table
What is the term for a frame with a destination MAC address unknown to the switch?
An unknown unicast
How long does a switch typically retain learned MAC address entries in its table?
5 minutes
Which layer does encapsulation occur?
The access layer.
What addressing information is recorded by a switch to build its MAC address table?
The source layer 2 address of incoming frames
