Test assumptions about ip subnet zero

Unanswered Question
Aug 19th, 2007

I am getting two stories about whether the current ccna exam assumes ip subnet zero and all 1s subnets are used.

Several of the practice exams I am using to study with operate on the premise that these two subnets are not available unless specifically stated in the question.

On the other hand I am hearing that the current 640-801 exam ALWAYS assumes these two subnets are available.

Can someone clear this up for me? Thanks in advance!

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
alwahidi22 Sun, 08/19/2007 - 09:20

Hi my friend,

By default if you asked about subnetting you should always know that ip subnet-zero command used , so subnet zero and all ones included unless you informed that ip subnet-zero not used.

By default IOS version 12 and later support ip subnet-zero.

For more information you can check this link:



Ibrahim Alwahidi


This Discussion