CCNA: Difference between revisions

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====Test 2====
====Test 2====
Do you _SEE_ the "collision domains" here:


[[Image: CCNA_Test2.png|400px]]
[[Image: CCNA_Test2.png|400px]]


10 "collision domains"
10 "collision domains"

Revision as of 17:28, 26 March 2010

WHAT

I'm trying to study to get my CCNA (640-802) degree :D I'm using my wiki to note what I'm trying to learn ! Much of the stuff here are from SYBEX CCNA Study guide (6th edition). Hope it'll help other people.

Software

I'm using GNS3 to emulate a Cisco environment. Get it from GNS3 Homepage

Internetworking Devices

Switches

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They work at Layer 2

They break up "collision domains" only.

Routers (Layer 3 switches)

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They work at Layer 3

Cisco calls them multiport bridges.

Advantages:

  • They break up "broadcast domains" by default ( 1 broadcast domain per interface ).
  • They break up "collision domains".
  • Can filter network based on Layer 3 ( Network Layer ) information ( e.g., IP Address )

Useful at:

  • Packet switching
  • Packet filtering
  • Internetwork communication
  • Path selection

Bridges

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They break up collision domains.



Hubs

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They keep all hosts in the same collision domain.

They often cause traffic congestion if on a busy network.

Traffic Congestion

Can be caused by:

  • Too many hosts in a broadcast domain
  • Broadcast storms
  • Multicasting

TEST

Test 1

Do you _SEE_ the "collision domains" and "broadcast domains" here :

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9 collision domains

- All hub network - 1 collision domain

- The bridge network - 3 collision domains

- The switch network - 5 collision domains

3 broadcast domains

- Only the router breaks up broadcast domains ! It has 3 connections.

Test 2

Do you _SEE_ the "collision domains" here:

Error creating thumbnail: File missing

10 "collision domains"