Test 2

LAN

Local Area Network, enables users to access the network

Distribution Layer

aka building backbone network, aggregation point for switches on different floors / at the access layer (Network arch comp)

Core Layer

like the real backbone, where all other network layers other than access are connected, expensive switches as switching is faster than routing, connects all buildings on campus (Network arch comp)

Data Center Layer

where servers are located, like a LAN for servers, servers grouped in server farms or clusters (Network arch comp)

WAN

Wide Area Network, private network we pay for, connects main and downtown campus (part of the enterprise edge) (Network arch comp)

Internet Access Component

Our connectivity to the internet, seperate router for internet and WAN (part of the enterprise edge) (Network arch comp)

E-commerce Edge

External servers that get their own section dedicated to them, servers that customers are hitting, used differently, handled differently, and managed differently than internal servers (part of the enterprise edge) (Network arch comp)

3 Phases of building block network design

needs analysis ( understand why the network is being built and what users and applications it will support), tech design (assess tech that fits users needs), cost assesment (relative cost of tech considered)

Capacity planning

estimating size and type of network circuits for each type of network (slow day vs. black friday)

bottleneck

circuit that is filled almost to capacity, critical point that determines quality of response time for users

Costs to consider in network projects

circuit costs, network devices, hardware costs, software costs, network management costs, test and maintenance costs, costs for Internet and WAN leased from carriers

RFP

Request For Proposal, specify equipment, software, and services desired and ask vendors to provide their best price

6 basic LAN components

client computer, server, NIC, network circuits, hubs/switches/APs, network OS (firewall NOT on list)

WLAN

Wireless LAN, use radio transmissions to send data between the NIC and the AP

2.4 vs. 5 GHz

2.4 further distance but slower, 5 faster but shorter range

Wireless AP

play the same role as a switch in a wired network

Switch

Data link layer, has a forwarding table, learns what MAC address connected to which port, after table built doesnt need to ask who's where but can just send traffic

CSMA/CD

Carrier Sense Multiple Access with Collision Detection, collision based contention technique that wired ethernet uses

CSMA/CA

Carrier Sense Multiple Access with Collision Avoidance, Wi-Fi attempts to completely avoid collision

Network security protocols

WEP -> WPA -> WPA2

When to do cableing for ethernet

easiest and cheapest during construction of building

Wi-Fi controller

manages multiple managed APs, reports devices attached to them and how busy each AP is, decides what AP devices connect to

Load balancer

aka load balancing switch, acts as a router at the front of the server farm

Routers

operate at network layer, perform more processing on a msg than switches so slower

VLAN switches

combo of layer 2 switches and routers, often called layer 3 switch

MDF (Main Distribution Facility)

rack of network equipment , devices connected using short cables called patch cables, primary hub of a network's cableing system

Chassis switch

key advantage is their flexibility, enables users to plug modules directly into switch

Redundancy

every piece of hardware after the access layer switch should have redundancy (especially core router which the picture left out)

VLAN

computers in different locations can be put in the same subnet using software rather than hardware

Drawbacks of VLANs

cost and management complexity

ACL (Access Control List)

specifies what traffic router should allow

6 Factors of WANs

cost,reliability, security, speed, redundancy, support

Ring architecture

connects all computers in closed loop with each computer linked to the next in a circle, messages can take a long time

Star architecture

connects all computers to one central computer, easy to manage, most susceptible to traffic problems

Full-Mesh architecture

every computer connected to every other computer, very expensive, not used much

Partial-Mesh architecture

many but not all computers connected to eachother, very common

T1 vs. T3 speeds

1.5 Mbps vs 44 Mbps

3 Types of packet-switched services

frame relay (very old), MPLS (newer, most common), Ethernet (very new, not fully implamented)

Site-to-site VPN

Provides virtual circuits between orgs offices over the internet

Remote access VPN

Uses software to connect to a VPN device at an office and enables employees to access an orgs network remotely

VPN adv and disadv

adv = low cost and flexibility, disadv = only as reliable as the internet connection, and security is a concern although most VPNs use encryption.

4 benefits of SDWAN (Software Defined WAN)

provides centralized management, reduces cost, provides more visibility over network traffic, good security

Improving WAN performance

increase computer or device performance, increase circuit capacity, or reduce network demand (unrealistic)

Server virtualization

process of creating several logically separate
servers on the same physical computer

Routed backbones

move packets along the backbone on the basis of their network layer address

Users path to core

User -> access layer -> distribution layer -> core