Network Devices (2.2)

Question 1

Router

Answer 1

Connects multiple switches, and their respective networks, to form an even larger network.

“Routes” traffic between IP subnets.

Makes forwarding decisions based on IP address.

Often connects diverse network types (LAN, WAN, copper, fiber, etc.).

Routers inside of switches sometimes referred to as “layer-3 switches”.

Question 2

Switch

Answer 2

Connects multiple devices to create a network.

Used strictly for LANs.

Forwards traffic based on MAC address.

The heart of an enterprise network.

Question 3

Unmanaged Swtich

Answer 3

Very few configuration options (Plug-n-play).

No VLANs.

Very little integration with other devices (no management protocols, i.e. SNMP).

Low price point.

Question 4

Managed Switch

Answer 4

Lots of configuration options.

VLAN support (interconnect with other switches via 802.1Q)

Whole host of other features (Spanning Tree Protocol, port mirroring, SNMP)

Question 5

Access Point

Answer 5

Not a wireless router, but communicates over wireless frequencies.

Simply a bridge to extend the LAN to wireless devices.

Makes forwarding decisions based on MAC addresses.

Question 6

Patch Panel

Answer 6

Combination of punch-down blocks and RJ-45 connectors.

Way enterprise networks organize their cables.

Question 7

Firewall

Answer 7

Filters traffic by port number.

OSI layer-4 device (tcp/udp).

Can encrypt traffic into/out of network.

Can proxy traffic for you (Firewall browses internet for you, inspects data, and then, if safe, sends to user).

Most firewalls can also be routers.

Question 8

PoE

Answer 8

Power over Ethernet.

One cable for both network and electricity.

Commonly used by phones, cameras, and wireless access points.

IEEE 802.3af (2003)

Type-1

15.4 watts DC, 350 mA max current

Question 9

PoE+

Answer 9

Power over Ethernet Plus

IEEE 802.3at (2009)

Type-2

25.5 watts DC, 600 mA max current

Question 10

PoE++

Answer 10

IEEE 802.3bt (2018)

Type-3 = 51 watts DC, 600mA

Type-4 = 71.3 watts DC, 960 mA

Question 11

Hub

Answer 11

“Multi-port repeater”.

Half-duplex.

Becomes less efficient as network traffic increases.

10Mbps/100Mbps throughput.

Very rare nowadays…

Question 12

Cable Modem

Answer 12

Transmission across multiple frequencies (hence the term broadband).

Data Over Cable Service Interface Specification (DOCSIS).

High speed networking.

Multiple services (data, voice, video, etc).

Question 13

DSL

Answer 13

(Asymmetric) Digital Subscriber Line.

Uses RJ-11 telephone lines.

Download speed is faster than upload.

~10,000ft limitation from Central Office (CO)

52Mbps down, and 16Mbps up

Question 14

ONT

Answer 14

Optical Network Terminal

Converts optical signal coming through fiber line into separate signals for TV, voice, and data.

Question 15

NIC

Answer 15

Network Interface Card

Fundamental network device.

Every device on network has a NIC, and needs one to connect to network in the first place (built-in Wi-Fi, Ethernet port on laptop, etc. are all NICs).

Often built into motherboard, or added as expansion card.

Question 16

SDN

Answer 16

Software-Defined Networking

Approach to networking that uses software-based controllers or APIs to communicate with underlying hardware infrastructure and direct traffic on a network.

Create software versions of physical hardware.