CH1: Intro to Networks Flashcards
What is a network?
Two or more connected computers that can share resources
Local Area Network (LAN)
Spans specific geographical area
- building
- department
- home office
- best practice split LAN into smaller work groups = admin easier
- router connects LANs
Workstations
powerful computers that run more than one CPU
Servers
- at service of network, provide services to hosts/clients
- run specialized software = network os to maintain/control network
- must have superior CPU, hard drive space, memory
- better performance if servers are dedicated
- file server
- mail server
- web server
- etc
Hosts
Any device with an IP address
Metropolitan Area Network (MAN)
metro area used to interconnect various buildings/facilities
Wide Area Network (WAN)
- internet
Characteristics - router
- large areas and connect disparate areas
- usually slower (than LAN)
- can choose how long to connect to WAN (LAN is all or nothing) [kinda like choosing to connect to the internet]
Internet
distributed WAN - made up of interconnected computers located in different areas
Internetwork - type of LAN/WAN that connects different logical networks
— made possible by routers
Personal Area Network (PAN)
close proximity connections
- bluetooth, infrared, zigbee
- usb, ethernet
Campus Area Network (CAN)
typically interconnects LANs on campus area
Storage Area Network (SAN)
exclusively for storage systems, interconnect servers to storage arrays
- found in data centers
Software-defined WAN
virtual WAN architecture
Multiprotocol Label Switching (MPLS)
one most popular WAN protocols
- physical layout flexibility
- prioritize data
- redundancy
- one-to-many connections
switching mechanism that imposes labels (#) on data and uses labels to forward data
Multipoint Generic Routing Encapsulation
protocol that dynamically creates and terminates connections
- no pre-configurations needed
-encap user data
-creates VPN connection
Main types of network architecture?
Peer-to-peer
Client-server
Peer-to-peer
No central authority
All computers are peers, connected together, all computers take on both client and server role
Best if:
- small # computers
- each user backups locally
- network doesn’t require much security
Client-Server
single server uses network OS to manage the whole network
- everything on special server
Good:
- scalability
- optimized network performance
Physical network topology
Location of all devices and cables on network - layout of network
Logical topology
Show how data moves on network
Bus topology
Has 2 distinct and terminated ends, all computers connect to one cable
- easy install + cheap
- hard to troubleshoot
- no fault tolerance
Fault tolerance
the ability of the network to respond to a condition automatically and resolve it
Star topology
Computers connected to central point with on cables or wireless connections
- more fault tolerant + scalable
- single point of failure - central point
What are the refined versions of the star topology?
Point-to-point link
wireless
Ring topology
each computer directly connected to other computers on network
- not scalable = have to break the ring
- pricey
- not fault tolerant! obvs
- hard to reconfigure
Mesh topology
connection from every machine to every other machine, lot of paths and connections, literal mesh
- full mesh least likely to have collison
n = hosts
n(n-1)/2 = # connections
Hybrid mesh topolgy
have connections to create redundancy (backup)
Point-to-point topology
direct connection between 2 routers/switches
- linked by serial cable = physical connection
- connected via circuit in frame relay or MPLS = logical
- not scalable
Point-to-Multipoint topology
connections from router interface to many other connections
router to multiple routers
Network backbone
All network segments and severs connect to - gives structure
Service related entry points
Demarcation point
- define points of responsibility
- carrier typically terminates with smart jack
Virtual networking
provide networking services without hardware, software only
- hypervisor = magic of virtual networking
—– software that allows for many virtual machines to run on one computer
