Ics 184 Networking Devices

Front 1

Switch:

Back 1

Layer 2/3 device

Uses MAC/IP addr.

Routes frames/packets

Front 2

Switch functions:

Back 2

(Like Bridge) Filters/Forwards/Learns

Creates Redundant Paths

Isolates device traffic

Creates separate collision domains

Front 3

How exactly do switches learn?

Back 3

stores own device address/port in mem table

Front 4

Init. step a new router always takes:

Back 4

Broadcasts addr. request to all connected devices

Front 5

Router vs. Bridge

Back 5

Rt : dedicated data lanes per each device/segment

Brg: single lane for all devices/Segs

Ltd. shared bandwidth

Front 6

Switches have two kinds of transmission

Back 6

Port switch: supports single net device

Segment switch : connects network segment

Front 7

Router purchase considerations:

Back 7

Bandwidth multiplocation = is bandwidth per port or overall

Full/half-duplexing

Front 8

Router vs. Layer 3 Switch

Back 8

Switch faster cuz different behavior and internals

Both filter/forward packets

Front 9

802.11 =

Back 9

Wireless Standard

Creates interfaces tween devices or device and base

Specifies MAC and phys layer protocols

Front 10

802.11a vs. 802.11b

Back 10

Both phys layer.

A is faster

Compat with Ethernet & DLL, not each other

Front 11

802.11a

Back 11

Common in Eurasia

5.7 GHz

For radio; single/multichannel

Impeded by walls

Frequency hopping = more secure

Front 12

802.11b

Back 12

Common for office wireless nets

2.4 GHz

Low enough freq = pass through walls

Direct sequence = reduced interference

Front 13

802.11g

Back 13

Best of a and b

A's speed with B's freq. (Pass walls)

Front 14

802.11n

Back 14

802.11g but with more antennas for data transmish

MiMo functional - multi-input/multi-output

Front 15

WLAN configs:

Back 15

All Wireless

Wireless Link

Mobile net

Front 16

Bluetooth =

Back 16

Short access range

For personal devices

Creates PAN

Uses radio

Front 17

Adapters =

Back 17

Lets compie interface to a net

Found in compie expansion NICs or as onboard circuit chip

Front 18

Network Converters

Back 18

Layer 1 hardware

Convert signals tween diff transmish media: coax -> FO or -> UTP

Front 19

802.15

Back 19

Bluetooth wireless stds.

2.4 GHz

Front 20

How bluetooth keeps comms secure?

Back 20

Shorter data packets

Uses frequency hopping spread spectrum

Encryption for sure

Maybe reqs authentication

Front 21

All wireless =

Back 21

Every device connects wireless, but may be stationary

(All wireless != mobile net)

Front 22

Mobile net

Back 22

When devices (laptops) in net move around and connect wirelessly

Front 23

Wireless Linked =

Back 23

Devices on each sep. seg wired to a base hub w/wireless capability

Removes need for inter-building cabling

Front 24

Frequency hopping spread spectrum:

Back 24

Each transceiver must know pseudorandomly generated freq. To chat

Front 25

Direct sequence spread spectrum:

Back 25

Reduces outside interference whether intentional or not

Front 26

Why pick an all wireless LAN?

Back 26

For aesthetic and safety in buildings with no beneath wall/floor space

Front 27

802.11 characteristics

Back 27

unlicensed band usage = free use as long as on freq.)

Front 28

Repeaters:

Back 28

Device that extends a segment, repeats signals signals passed and supplies power to sigs

Front 29

Repeater does not:

Back 29

Filter, evaluate, or change signals

Front 30

Diff tween what analog and digital repeaters do?

Back 30

Analog just amplifies signal / make loud

Digi takes sig, regenerates the bits, and passes it along

Front 31

When no use repeater?

Back 31

On heavy use net

Between two networks/ net segs

Front 32

What do digi repeaters introduce to a net and why? Why bad

Back 32

Introduces delays to a net because sig regen takes time

Bad cuz throws off network clock

Front 33

5-4-3 rule

Back 33

Rule for repeaters

Max of 5 segs connected with 4 repeaters between each

Only 3 of 5 segs allowed to be to split off more than 1 way

Front 34

Hubs =

Back 34

Central unifying point that extends segment and allows adding multi devices to net

Front 35

Repeater limits

Back 35

Use in small geo areas/small lans

Extend no more than 100m

Front 36

Hubs do not ___ but instead __ as far as data transmish

Back 36

Filter info, just repeats what's received to all other nodes including sender

Dumb

Front 37

Hubs are logically a what?

Back 37

Shared bus/multi-repeater

Front 38

Collision domain:

Back 38

Area where data packets can collide

Nodes compete to talk

One talks, all hear

Can include multiple hubs

Front 39

Example of bad collision domain:

Back 39

2 net hubs connected w/out bridge:

If node of one hub broadcasts, it'll every node on both hubs

Front 40

Network segment

Back 40

Group of nodes that all talk over same phys layer devices

Segs separated by hubs, routers, and switches

Front 41

Hubs pka?

Back 41

Wiring Concentrator

Front 42

Collision domain size based on

Back 42

# of nodes

Front 43

Repeaters and hubs are:

Back 43

Phys layer devices

Front 44

Bridges:

Back 44

Device that separates collision domains

Filters data and forwards to proper location

Front 45

Most common hub:

Back 45

Ethernet hub

Front 46

Simplest bridge found where:

Back 46

Inside a NIC

Front 47

Bridge can meet how many networks/segs

Back 47

2

Front 48

Bridges learn how?

Back 48

Create and retain bridging table of which devices on which side as the devices send message

Front 49

Like switch cache, how are bridging tables created?

Back 49

Broadcast to all users "where are you"

Front 50

2 bridges to same net seg/node bad why?

Back 50

Can result in active loop where bridges send info in circle cuz of messed up ports

Front 51

Bridges separating collision domains help:

Back 51

Increase net performance and offer connectivity tween LANs for WAN

Front 52

Bridging domain:

Back 52

Encompasses any layer 2 devices of net seg

Front 53

Bridges and specific switches are

Back 53

Layer 2 devices