2 Replies Latest reply: Jun 7, 2011 2:11 PM by Martin

# Which two address can be assigned to a host with a subnet mask of 255.255.254.0?

Which two address can be assigned to a host with a subnet mask of 255.255.254.0?

Ans:

186.54.3.0

26.35.2.255

Can anybody explain this question ???

• ###### 1. Re: Which two address can be assigned to a host with a subnet mask of 255.255.254.0?

With these types of questions you need to ask yourself the following questions.

What is the FVH?

What is the LVH?

Then you can see if the address in question fits within the range of valid hosts.  Ok...lets take each one independently.

A mask of 255.255.254.0 = /23 means two /24s.  So the networks are counting by "2" in the third octet:

186.54.0.0/23

186.54.2.0/23  ---> belongs here

186.54.4.0/23

Now we can answer the questions above.

What is the network address? 186.54.2.0

What is the FVH? 186.54.2.1

What is the LVH? 186.54.3.254

So, 186.54.3.0 is a valid host address within the network 186.54.2.0/23

Again, we are counting by "2" in the third octet.

So the networks for this address are:

23.35.0.0/23

23.35.2.0/23   ---> belongs here

23.35.4.0/23

What is the network address?  23.35.2.0

What is the FVH? 23.35.2.1

What is the LVH? 23.35.3.254

So, 23.35.2.255 is a valid host address within the network 23.35.2.0/23

HTH

• ###### 2. Re: Which two address can be assigned to a host with a subnet mask of 255.255.254.0?

Search forum for some tips and for Magic Number (or Multiplier);

Magic number is 256 - 254 =2 that happens to be in 3rd octet, so  in that octet,

you can start counting from 0, add 2, +2=4, 6, 8, 10, ....

then follow Brian's explanation on why is valid IP