Types: 1. multimode = carry LED signals 2. single-mode = carry laser signals (can support longer run lengths than multimode can)

single common shared cable - first ever topology - physical and logical topologies match - not secure - not scalable - not fault tolerant - access method: Ethernet + CSMA/CD

bus wrapped in on itself - token passing: access method - not fault tolerant - not secure - not scalable - guaranteed bandwidth / throughput when you had token

easier to add new devices than bus - physical star, logical bus - single node fault tolerance - single point of failure: hub

- plays sound through wire - useful for unlabeled wires

WiFi - half-duplex - 2.4 or 5 GHz - uses DSSS, OFDM, or MIMO-OFDM

Other Flashcards by Rebecca Preib

Fiber optic cabling

Types:

multimode = carry LED signals
single-mode = carry laser signals (can support longer run lengths than multimode can)

How well did you know this?

Not at all

Perfectly

Frequency-division multiplexing (FDM)

uses different carrier signals operating at different frequencies to transmit different streams

How well did you know this?

Not at all

Perfectly

Time-division multiplexing (TDM)

breaks each conversation into different frames called time slots, which take turns using a single shared channel

How well did you know this?

Not at all

Perfectly

Space-division multiplexing (SDM)

uses multiple parallel physical connectors to transmit different streams

How well did you know this?

Not at all

Perfectly

Network and Troubleshooting Model

Identify problem
Establish theory of probably cause
Test theory to determine cause
Establish plan of action to resolve problem
Implement solution or escalate
Verify full system functionality and preventative measures
Document findings, actions, and outcomes

How well did you know this?

Not at all

Perfectly

Troubleshooting Phases

Identification (learning that there’s a problem)
Diagnosis (determine extent and root cause of problem)
Resolution (plan and implement fix)

How well did you know this?

Not at all

Perfectly

Bus Topology

single common shared cable

first ever topology
physical and logical topologies match
not secure
not scalable
not fault tolerant
access method: Ethernet + CSMA/CD

How well did you know this?

Not at all

Perfectly

Ring Topology

bus wrapped in on itself

token passing: access method
not fault tolerant
not secure
not scalable
guaranteed bandwidth / throughput when you had token

How well did you know this?

Not at all

Perfectly

Star Topology

easier to add new devices than bus

physical star, logical bus
single node fault tolerance
single point of failure: hub

How well did you know this?

Not at all

Perfectly

Mesh Topology

high availability

# endpoints = n (n - 1)
# links = (# endpoints) / 2

How well did you know this?

Not at all

Perfectly

Cable tests

ex: wiremap, continuity, cable length

How well did you know this?

Not at all

Perfectly

Toner probe

plays sound through wire

- useful for unlabeled wires

How well did you know this?

Not at all

Perfectly

Time-Domain Reflectometer (TDR)

tells you how long cable is
can use to tell where break in line is
OTDR is used for fiber optic
cable certifier is used for copper

How well did you know this?

Not at all

Perfectly

IEEE 802.11

WiFi

half-duplex
2.4 or 5 GHz
uses DSSS, OFDM, or MIMO-OFDM

How well did you know this?

Not at all

Perfectly

IEEE 802.11a

frequency = 5 GHz
data rate = 54 Mbps
modulation = OFDM
MIMO streams = N/A

less chance of interference due to 5.0 band

How well did you know this?

Not at all

Perfectly

IEEE 802.11ac

frequency = 5 GHz
data rate = 1 Gbps+++
modulation = MIMO-OFDM
MIMO streams = 8

MU-MIMO increases throughput

How well did you know this?

Not at all

Perfectly

IEEE 802.11b

frequency = 2.4 GHz
data rate = 11 Mbps
modulation = DSSS (direct sequence spread spectrum)
MIMO streams = N/A

How well did you know this?

Not at all

Perfectly

IEEE 802.11g

frequency = 2.4 GHz
data rate = 54 Mbps
modulation = OFDM
MIMO streams = N/A

How well did you know this?

Not at all

Perfectly

IEEE 802.11n

frequency = 2.4 / 5 GHz
data rate = 108 - 300 Mbps
modulation = MIMO-OFDM
MIMO streams = 4

introduced channels to MIMO

How well did you know this?

Not at all

Perfectly

IEEE 802.2

ethernet

How well did you know this?

Not at all

Perfectly

IEEE 802.3af

Power over Ethernet
(also 802.3at)

PoE = 802.3af @ 15.4 Watts
PoE+ = 802.3at @ 31 Watts

How well did you know this?

Not at all

Perfectly

Security Policies

documents with broad overview statements

ex: Acceptable Use Policy (AUP), Remote Access Policy, password policy, IT Safety Policy, NDA, License Restriction, International Export Control, Network Use Policy

Posture assessment

Cisco service that allows you to check the state, AKA posture, of all the endpoints that are connecting to a network for compliance w/corporate security policies

allows you to control clients access to protected areas of network

cable modem

connects to internet via coax cable with F-type connector

- used for DSL

Windows logs

1. Application 2. Security 3. Setup 4. System / General 5. Forwarded Events

NAT routers

- replace source IP address with its IP address | - restore original IP header when a response comes back so that the results can be sent to the originator

Inter-VLAN Routing

is implemented in switches to enable communication between VLANs

Route Metric Elements

- MTU (Maximum Transfer Unit) size - cost - bandwidth - hop count - latency

multicast

244.x.x.x used to distribute data to multiple recipients ex: audio / video streaming broadcasts

hypervisor

computer software, firmware, or hardware that creates and runs virtual machines type 1 = runs directly on hardware independent of host OS (bare metal) type 2 = runs on top of OS (hosted)

Ethernet Frame # of Bytes

1,500 Bytes Jumbo frame = 9,000 Bytes

socket

IP + port #

straight through cable

connect unlike devices ex: PC - hub, PC - switch, switch - router

rollover cable

console cable - used to manage network device ex: (DB-9) serial port console router switch/RJ45 (USB) (RJ-45) (USB) (USB)

crossover cable

connect like devices ``` ex: PC-PC hub-hub switch-switch hub-switch PC-router data port ```

dial-up

- requires a modem - connects to internet via phone # - uses PPP - is slow

default gateway

IP address of the router interface that connects to the LAN AKA: how to get to the Internet

types of firewalls

1. stateless: use pattern analysis and heuristics | 2. stateful: examine each packet

symmetric encryption

same key to encrypt and decrypt ex: AES, DES, RC4, IDEA, Blowfish

asymmetric encryption

public + private keys public key encrypts private key decrypts key pair = public + private keys ex: RSA, Elliptic curve crypto, Diffie-Hellman key exchange

ping of death

ICMP packet larger than normal errored routes

smurf attack

broadcast where sender is spoofed victim

packet switching technologies

1. Frame Relay - phased out for ATM 2. ATM (Asynchronous Transfer Mode) - being phased out 3. MPLS (Multiprotocol Label Switching) - most common today *mainly used by ISPs*

half-duplex

can't send and receive at the same time

full-duplex

can send and receive at the same time

broadband

can carry multiple signals at once

baseband

only carries 1 signal at a time (1 signal consumes entire bandwidth)

2 main routing protocols

1. interior | 2. exterior

interior routing protocols

1. distance vector protocol (IGRP, RIP, RIPv2, RIPng) 2. Link State Protocol (OSPF, IS-IS) 3. hybrid (EIGRP)

exterior routing protocol

BGP (Border Gateway Protocol) - AS (autonomous system) - Path Vector

multi-modal distortion / modal dispersion

distortion mechanism occurring in multi-mode fiber optic cable in which the signal is spread in time because the propagation velocity of the signal is not the same for all modes

DHCP Relay

enables a single DHCP server to service more than one broadcast domain

SNMP PDUs

``` get set trap response walk ``` sent between NMS (running on SNMP manager) and managed devices (using MIB)

HOSTS file location

C:\\Windows\System32\Drivers\etc