Lesson 3 - Chapter 2: Ethernet Flashcards
What is a protocol?
a set of rules to follow/communication standard
(using certain language/shared vocabulary and rules that make communication between devices easier)
The standards that define everything needed to get data from one computer to another is called what?
Ethernet
What are Ethernet flavors?
The improvements made to Ethernet over the years, and the variety of ways that Ethernet is implemented
Most modern Ethernet networks employ 1 of what 4 speeds?
- Ethernet (10BaseT)
- Fast Ethernet (100BaseT)
- Gigabit Ethernet (1000BaseT)
- 10 Gigabit Ethernet (10GBaseT)
For the Ethernet network speeds (1000BaseT for example), what does the number indicate and its measurement? What does “Base” mean? (2)
The “1000” means the Ethernet speed measured in Mbps.
The “Base” means baseband, which uses the entire bandwidth of the cable to carry Ethernet data
What’s the difference between baseband and broadband?
Baseband - uses the entire bandwidth of the cable to carry Ethernet data
Broadband - allows multiple data streams to share the medium
What type of Ethernet cables would you find in a typical home or small business network?
Unshielded Twisted Pair (UTP) cables
What are UTP cables?
cables that carry data on twisted pairs of copper wires
In “100BaseT” Ethernet speed, what does the T stand for?
Twisted, as in UTP
Instead of T, what letter would Ethernet cables use if they use fiber optic cable instead?
Since T = Twisted (UTP), fiber uses other letters like FX
What is a network’s topology?
describes how the network components are connected to each other (physical or logical)
What’s the difference between physical and logical topology?
physical topology - how each component is physically cabled to another
logical topology - describes how data flows through the network
What are the 4 types of physical topologies?
- star
- bus
- mesh
- ring
What does a switch provide?
A switch provides a common point of connection for network devices
How many ports do consumer-level switches have?
4-8 ports
How many ports do business-level switches have?
32 or more
Can multiple switches be chained together?
yes
What’s the most popular network topology in use today?
the physical star (hosts connect to a central box like a switch, data passes through the box to travel around)
What logical topology is in use today?
Since the earliest Ethernet networks used a physical bus topology, the physical arrangements have changed but logically Ethernet still uses a bus topology to transfer data
Early Ethernet star topology networks used a hub instead of a switch. What’s a hub?
(stupid repeaters)
anything sent in one port automatically went out to all the other connected ports (hosts)
How are switches and hubs different?
hubs = stupid repeaters
switches = smart repeaters (memorize the MAC addresses of all connected devices and only send signals to the correct host)
The connection between a computer and a switch is called?
a segment
Can you use a splitter on an Ethernet cable in a star bus topology like with cable TV and other network types?
No because the switch assumes that the data that’s incoming is coming from a single source (so you can’t split the source)
What’s a benefit of the star bus topology?
the entire network doesn’t go down if a single cable breaks (but it would if the central switch failed)
Ethernet segments are limited to how many meters (or less)?
100 meters (or less) = roughly 300ish feet
What are the 2 types of switches?
- managed
- unmanaged
What’s the difference between a managed and unmanaged switch?
unmanaged = a smart device that automatically is configured to allow devices to communicate via MAC addresses (tl;dr connection device)
managed = configuration options available at the switch’s IP address and software for extra features
VLANS are a type of what kind of switch?
Virtual Lans are a type of managed switch
What can you use VLANs for?
Break up/segment a single physical network into 2+ distinct networks
(computers within the same VLAN can talk to each other, but not outside it)
What is PoE?
Power over Ethernet enables a single cable to act as both data and an electrical conduit to a device
(useful for deploying security cams with no AC outlet nearby, just connect to a compatible WAP or switch)
What feature in a switch supports PoE?
power injector
How can you add PoE functionality to a switch or router that doesn’t natively support it?
by adding a midspan injector
What are the 3 standards for PoE?
- 802.3af (oldest, Type 1, 15.4 watts, VoIP, WiFi)
- 802.3at (Type 2, 30 watts, video IP phones, tilt cameras, alarms)
- 802.3bt (Type 3, 60 watts, IP cameras, laptops, video IP phones)
- 802.3bt (Type 4, 100 watts, same as 3)
