2.2 Networking Hardware

Question 1

Routers

Answer 1

• routes traffic between IP subnets (network within a network)
• often connects LAN to WAN
• layer 3 device
• often connects diverse network types together (LAN, WAN, copper, fiber

Question 2

Switch

Answer 2

• connects devices in a network
• forwards traffic based on data link address (MAC address)
• many ports and features
• core of an enterprise network

Question 3

Unmanaged Switches

Answer 3

• very few configuration options
• no VLANS
• little integration with other devices: no management protocols, no SNMP capabilities

Question 4

Managed switches

Answer 4

• layer 2 switch with configuration features
• VLAN support
• traffic prioritization
• redundancy support: STP prevents loops between switches
• port mirroring
• external management: SNMP capabilities

Question 5

Access Point

Answer 5

• provides wireless connectivity for the local network (creates WLAN)
• “bridge”: extends a wired connection into a wireless connection
• makes forwarding decisions based on MAC address
• ex. a router with WiFi capabilities

Question 6

Central Wiring Closet

Answer 6

• main infrastructure of a network
• all devices are connected to its patch panel
• other side of the patch panel may have other connectors which then connect to interfaces on a switch

Question 7

Patch Panels

Answer 7

• combination of punch-down blocks and RJ-45 connectors
• cables are permanently punched down to a patch panel
• cables going to the switches can be unplugged when a change needs to be made

Question 8

Firewalls

Answer 8

• filters traffic by IP address and port number
• for security purposes
• OSI layer 4
• can encrypt traffic into/out of the network
• can proxy traffic
• most firewalls can also be a layer 3 device (router)

Question 9

PoE

Answer 9

Power Over Ethernet
- one cable provides both network connection and power
- injector supplies power to PoE cabling
- endspan: power provided at the switch
- midspan: in-line power injector when the switch doesn’t support PoE

Question 10

PoE Switch

Answer 10

• Commonly marked on the switch or interfaces
• blue color over the ports = supports PoE

Question 11

PoE: IEEE 802.3af

Answer 11

15.4 watts DC power, 350 mA max current

Question 12

PoE+: IEEE 802.3at

Answer 12

25.5 watts DC power, 600 mA max current

Question 13

PoE++: IEEE 802.3bt

Answer 13

Type 3: 51 watts, 600 mA max current
Type 4: 71.3 watts, 960 mA
10GBASE-T
aka 4PPoE

Question 14

Hub

Answer 14

• commonly used to connect devices on a network before switches
• multi-port repeater: traffic going into one port is repeated to every other port
• half-duplex: data can only be sent in one direction at a time
• less efficient as traffic increases
• 10 megabit/ 100 megabit

Question 15

Cable modem

Answer 15

• broadband communication: transmission across multiple frequencies (television signal, internet data, phone lines)
• DOCSIS: Data Over Cable Service Interface Specification
• speeds up to 1 Gbit/s
• coaxial cable
• shared bandwidth

Question 16

Digital Subscriber Line (DSL)

Answer 16

• internet through a telephone company
• ADSL: asymmetric because download speed is faster than upload speed; faster speed and handles more data at once
• copper cabling
• dedicated bandwidth

Question 17

Optical Network Terminal (ONT)

Answer 17

• connection to fiber network
• connects ISP fiber network to the copper network
• demarcation point in a data center or outside a home

Question 18

Network Interface Card (NIC)

Answer 18

• used to connect to a copper ethernet connection
• every device on the network has a NIC inside of them (ex. computer, servers, printers, routers)
• specific to network type (ethernet, WAN, wireless)
• often built into the motherboard, sometimes an expansion card

Question 19

Software Defined Networking (SDN)

Answer 19

Architecture designed to make a network more flexible and easier to manage. It splits networking devices into different functional planes of operation

3 Layers:
1. Infrastructure/ data plane
- process the network frames and packets
- forwarding, trunking, encrypting, NAT
2. Control/ control plane
- manages the actions of the data plane
- routing tables, sessions tables, NAT tables
- dynamic routing protocol updates
3. Application layer/ management plane
- configure and manage the device
- SSH, browser, API
- ex. intrusion detection, firewall, and load balancing