2 Link-Layer Networking and Ethernet Free Online FlashCards

What does the physical layer do?

The physical layer sends bits as signals over a medium such as copper cable, optical fiber, or a radio channel.

What device forwards traffic between different IP networks?

A router forwards traffic between links when communication must cross different IP networks.

Which IEEE standard describes Ethernet data-link functions?

Ethernet is a widely used family of wired LAN technologies standardized by IEEE 802.3.

What does a MAC address identify, and how is it typically written?

A MAC address identifies a link-layer source or destination and is typically written as six hexadecimal octets.

What does an Ethernet FCS do?

The Frame Check Sequence (FCS) lets a receiver detect certain transmission errors; it does not correct them.

How does a switch learn MAC address locations?

A switch examines incoming frames’ source MAC addresses and records which addresses are reachable through which ports.

What effect does a VLAN have on a switched network?

A VLAN divides a switched physical network into separate logical LANs, placing devices in different VLANs in different broadcast domains.

What is the data-link layer responsible for?

The data-link layer organizes bits into frames for delivery across one local link or LAN, providing link-level addressing and frame-boundary handling.

What information does an Ethernet length/type field provide?

The length/type field indicates the payload length or, in common Ethernet II frames, the payload protocol type.

How is the conventional Ethernet frame size counted?

A basic Ethernet MAC frame is conventionally 64 to 1518 bytes, counted from the destination address through the FCS; the preamble and start-frame delimiter are excluded.

How does a switch handle a frame with a known destination MAC?

When a destination MAC address is known, a switch forwards the frame toward the port associated with that address.

How does a switch handle an unknown destination MAC?

A switch generally floods a frame with an unknown destination to other ports in the same VLAN, except the port where it arrived.