of 12

Networking Basics

Published on 2 weeks ago | Categories: Documents | Downloads: 3 | Comments: 0
154 views

Comments

Content

Ethernet Basics and Network Troubleshooting Wires, switches, hubs, and what to plug where

Networking  

Communication between two or more devices. Parts required for Networking: 

Host  



Card   



Computer, networked printer, etc. Sends/receives data for network to card Every card on a network has to have a unique address Card breaks outgoing data into packets and addresses them Card receives packets addressed to it and re-assembles re -assembles packets to data

Wire  

Transmits packets across network For this discussion includes all wires, radios and devices between network cards (including hubs, switches, access points, etc.)

Wire types 

Co-Ax 

Composed of: 



10 Mb only



10Base5 “Thicknet” 



1600 ft (500 meters)

10Base2 “Thinnet” 



Core, insulation, shielding, insulation

600 ft (200 meters)

Twisted Pair  



10/100/1000 Mb 340 ft. (100 meters) between devices CAT3, CAT5, CAT5e, CAT6, CAT6e

Wire Types (cont.) 

Fiber 10/100/1000/10,000 Mb Multi-mode – Long Haul (20 km) Single-mode – “Short Haul” (3 Km) what we use Carries light, not electricity Wireless Speeds 11/7 Mb, 54/27Mb Because of encryption and connection upkeep, available bandwidth is about ½ of stated speed   





 



Common “mediums”   

InfraRed (IR) Microwave, (long distances) Radio Licensed/private Un-licensed (802.11b/g/a)  

Ethernet (Infancy) 

10Base5 – “Original Ethernet” Large Co-ax Backbone (garden hose) Terminated at ends Vampire tap, to transceiver 1600 ft. backbone 

   



“Jumper” from transceiver

to card How it works: 10 Mb/s  

One Wire… every packet

goes to every host CSMA/CD (Carrier Sense Multiple Access/ Carrier Detect) Collisions Half Duplex 

 

Ethernet (Toddler) 

10Base2 

 



  

Smaller diameter, less expensive cable shorter length 600 ft total length Get rid of the “backbone” use a “T” connector on

each card Daisy chained the whole network together Terminated on ends Still ONE WIRE Still CSMA/CD

Ethernet (Adolescent) 

10BaseT 

HUB 



 





Packet is simultaneously sent out all ports If two packets come in at the same time it is a collision

Twisted pair wire The Hub is part of “The Wire”

340 feet between devices 3 hops maximum (no daisy chaining)

Server is slow/not working 

Work this with your NE!! What you *CAN* do



Step 1





Un-plug/re-plug the server’s network cables  





First Contact helpdesk/your NE. Don’t move them, plug them back in

the same place Only do one end of one cable at a time

The server will be “down” while they

are un-plugged 

Step 2 (still not working) 



Check it out, or have the network guy check it out Contact helpdesk/your NE, get server restarted

Group of computers is slow/not working 

What do they have in common? 

 All connected to same hub? 



Get a switch!!!

 All connected to same mini-switch?   



Power-cycle switch Check for loops Replace switch ($18.00 for 8 port.) Change port on IDF/MDF

Group of computers is slow/not working (cont.) 

What do they have in common? (cont.) 

 All same model/from same image?   

 

Virus/Spyware in image? Client software installed/configured wrong? OS not patched? Bad NIC driver?

Same “wing” or area 

Power cycle switches in IDF/MDF (some of these take over 3 min. to boot, so don’t just go and do

this without warning users)

Single computer is slow/not working  



Restart the computer Un-plug/re-plug/replace cables Check it’s connection at

MDF/IDF

Single computer is slow/not working (cont.) 

 

 

Change it’s port at MDF/IDF 

Don’t move other wires



Don’t “clean up” wiring!!!



If it doesn't fix it, change it back

Patches/ AntiVirus / Spyware Upgrade/Re-install NIC driver Replace NIC Force speed/duplex (gig switch, Cat5 wiring?)

Sponsor Documents


Recommended

No recommend documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close