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smart Z

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Question on Zero-subnet in the test

Hi Experts.

I am confused.

I have a question that says assign the 3rd usuable subnet to the serial interface of the router but note the sub zero subnet is not usable. The network is 192.168.1.0 / 240. this is just an example. Assign the last usable IP from the 3rd usuable subnet.

I know the first networrk is 0
2nd is 16
3rd is 32

What is my answer and shall i still consider the network 0 even though the question tells me to consider subnet zero is not usuable.

Thanks,
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Sandy
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it depends on what device you are using this zero subnet because some of the devices are using the zero subnet.

http://www.petri.co.il/csc_ip_subnet_zero.htm
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David Akinsanya
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Assign the last usable IP from the 3rd usuable subnet.

Answer = 192.168.1.62

Pardon my typo above

Your 1st subnet is 192.168.1.16 - 192.168.1.31
2nd Subnet is         192.168.1.32 - 192.168.1.47
3rd Subnet is          192.168.1.48 - 192.168.1.63

Your last assignable address in the 3rd subnet would therefore be
192.168.1.62
the .63 is a broadcast address and is not assignable
One does wonder why someone is teaching IP subnetting/addressing techniques that are 15 yrs out of date...
It is obsolete and I agree, but it is still valid and available for whoever wants to use it.

I think the question is focused on testing the student's understanding of ip subnet-zero.

You will be amazed at how many Engineers lack the understanding.

I wouldn't write the question off though.

Just to recap
With ip subnet-zero enabled, your first usable subnet is 192.168.1.0 - 192.168.1.15
With ip subnet-zero disabled, your first usable subnet is 192.16.1.16 - 192.168.1.31
I wasn't writing off the question, I answer a number of questions on EE that come with the advice "but don't do it that way"...  I just hope whoever's teaching the class provides the caveat that ip subnet-zero should not be used in anything other than a historical example...  

As to being amazed, I tend, rather, to be jaded on the lack of ability/understanding even at the carrier level...  Oh well...
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smart Z

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Thank you all.

I know the difference now with your superb explanation.