Ich hab noch paar Comments von den orig. Cisco Forums rauskopiert:
This is exactly right. Unless the question specifically states "IP subnet-zero is in use", as far as CCNA is concerned, the first and last subnets are verboten.
This will reverse in CCNP, when you assume the use of IP subnet-zero unless it specifically tells you not to.
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There are a couple different ways to ask the questions ...and they'll have different answers.
One way would be to ask "How many TOTAL subnets ....."
Another way to ask might be "How many USABLE subnets ..."
"Total" would ALL subnets, "Usable" would be "-2" (at least for the sake of the test).
Read the questions carefully when you take the test: they are not trying to trick you, but they will provide several answers that are the outcome of common calculating mistakes.
Take the question as presented, don't try to read something into it.
What works for me is to read the actual question (usually the last sentance), then go to the beginning and read the entire scenario. Knowing what question the scenario is providing the information for allows you to filter out the useful information from the non-useful info.
I also find it helpful to create all your grids & "helpers" before you hit the "enter" button to begin the actual test. Once the test has started and the timers is counting down, it is easy to forget.
Take the time to do the familiarization practice offered before the actual exam begins ... it does not count against your exam time and will same you (at least) a few minutes of figuring them out during exam-time.
Good Luck
Scott
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Scott is of course right about taking the question as it is presented: watch for "total" and "usable" subnets.
What works for me is before I attempt to answer any question, I read the question (and possible answer options) through three times. A drag? Yes, but it minimises the chance of misreading the question.
As far as the CCNA exam is concerned, I think Lammle (assume the subnet zero command is available) is wrong and Chris (assume the subnet-zero command is not available) is right.
Good luck in the exam,
Josef.
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ip subnet-zero is indeed enabled by default.
Kevin's right... organizations use the zero subnet regularly, but for the CCNA exams, pretend they don't.
Good luck!
Chris Bryant
CCIE #12933
Quellenverweis: selber auf Cisco.com suchen
