3 Ethernet and Network Devices Free Online FlashCards

What does Ethernet carry across a local link?

Ethernet is a family of wired local-area networking technologies standardized as IEEE 802.3; it carries data in frames across a local link.

What does a frame’s destination MAC address identify?

The destination MAC address identifies the intended receiver on the local link.

What is the purpose of an Ethernet FCS?

The Frame Check Sequence (FCS) lets a receiver detect a damaged frame; it detects errors but does not repair them.

What is a common MAC address format, and is it always factory-set?

A common MAC address is 48 bits, written as six hexadecimal pairs. Addresses may be globally assigned or locally administered, so they are not always permanent factory-set identifiers.

What do unicast, multicast, and broadcast MAC destinations address?

Unicast identifies one interface, multicast identifies a group, and broadcast addresses all devices on the local broadcast domain.

What destination MAC does a host use to reach a different IP network?

For traffic to a different IP network, a host sends the local Ethernet frame to its default gateway’s MAC address; the router forwards the IP packet onward.

How does an Ethernet switch learn which devices are on which ports?

A switch learns by recording the source MAC address and incoming port for each received frame.

When does a switch flood a frame to other relevant ports?

A switch floods an unknown-destination frame, or a broadcast, to the other relevant ports in the local network or VLAN.

How does a router decide where to forward a packet?

A router connects IP networks and forwards packets according to their destination IP addresses and its routing information.

What usually changes at a routed hop: MAC addresses, IP addresses, or both?

At each routed hop, the router sends the packet in a new link-layer frame. The MAC addresses usually change at each hop, while the packet’s end-to-end IP addresses generally remain the same.

What does a wireless access point typically do?

A wireless access point lets Wi-Fi devices connect to a network and typically bridges their traffic to a wired LAN; it does not necessarily route between IP networks.

How does a hub or repeater handle traffic?

A repeater regenerates or retransmits signals without address-based forwarding decisions. A hub is a legacy multiport repeater that repeats incoming bits to its other ports.