Zero Subnet

jcblester

I just took a practice exam and one of the sims I missed was due to the zero subnet. It stated that it wanted me to find the subnet mask with a max of 6 hosts. The IP range is 192.168.1.0 /24. Use the first available host on the first subnet for R1 S0 and the second available host on the first subnet for R2 S0. I came up with the mask /29 witch was correct and the first host address as 192.168.1.1. R2 S0 address was 192.68.1.2. I thought I was correct on those also. They said the correct first available host was .9 and the second was .10. In the explantion I finally understood the zero subnet deal but how do you know when it comes into play when they don't mention it in the question?

Pash

The CCNA FAQ links to this post here regarding IP Subnet Zero:-

http://www.techexams.net/forums/viewtopic.php?t=15720

Maybe the question you were doing is dated. All later versions of IOS as in 12.0+ have ip subnet zero enabled by default. This question has been asked many times before, but according to the guys who are trainers on this board, assume for the exam IP subnet zero is on.

Cheers,

jcblester

Point Taken!

Thanks