Some discrepencies between study materials

flammablecamel

I've used multiple sources to prepare for the net+ and I get different information from different sources, very frustrating. Was trying to get some of this cleared up.

My sybex net+ 4th edtion book says that 1000baseLX is 550mm 2000sm but the technotes here say 550 mm 5000sm(talking segment length).

Plantwiz

First,
This is why it is important to use more then 1 source. So it maybe frustrating, but going all the way back to schooldays you likely had teachers and Professors encourage you to use more then one source. No different in the 'real world'

Second,
I don't have the Sybex book, how is this discrepancy worded? Using two sources there may not be reporting on the same thing.

Third,
have you check the errata for Sybex? Any errors or reported corrections will be there.


Last,
I'll try to see if I can find both in their original context, however I'm suspecting one is reporting about one thing and the second another. Also, for cable discrepancies....one can always go straight to the governing body.... www.ieee802.org/3 and
http://standards.ieee.org/getieee802/

flammablecamel

Well I was hoping someone could tell me what the correct segment lengths are for 1000baseLX I've seen the following different answers.

sybex 4th edition
550meters multimode fiber 2000meters singlemode fiber

All in one network+ certification (its a 2003 book kind of outdated probably)
5000meters singlemode fiber

technotes on this forum
550meters multimode fiber 5000meters singlemode fiber

Also I was wondering if you have to subtract 2 from your total number of networks when subnetting since I seem to get a different answer wherever I look.(not talking about the # of hosts)

Devin McCloud

Exam prep 2 2005 says:
Half-duplex 316m (multimode and single-mode fiber);
full-duplex 550m (multimode fiber);
full-duplex 5000m (single-mode fiber)