Subnet Question related to Class B Network

vlrkvlrk Registered Users Posts: 6 ■□□□□□□□□□
[COLOR=rgba(0, 0, 0, 0.87058icon_cool.gif][FONT=&quot]Question: What valid host range is the IP address a part of?

The answer it show's as "[/FONT][/COLOR][COLOR=rgba(0, 0, 0, 0.87058icon_cool.gif][FONT=&quot] through to".

Where as my calculation is getting different address as through to

The way of calculation is as below.

1. The address is of class B , So first two octets are of network bits + third octet 8 bits + 1'st bit of fourth octet.

2. So address range will start like this first n/w - , second n/w , third n/w - .. so an..

3. In this manner the valid host range for should be -

Can any one please let me know , where my understanding is wrong in this case.



  • rob42rob42 Member Posts: 423
    Your forgetting about the Network Address [] and the Broadcast Address [], so the 'Valid Host Range' is .1 to .126.
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  • vlrkvlrk Registered Users Posts: 6 ■□□□□□□□□□
    thanks rob.. it skipped out of my mind.
  • dontstopdontstop Member Posts: 579 ■■■■□□□□□□
    By "host" range they're referring to addresses that can be assigned to a host machine. The network (first address) and last address (subnet broadcast address) are reserved.

    For instance: has an address range of <- reserved (Network Address) <- First host address
    . <- Last host address <- (Network Broadcast Address)
  • Uriah7Uriah7 Member Posts: 45 ■■□□□□□□□□
    The host address is actually classless due to the subnet mask being provided in the question. Your step 2 is correct for a classful network, but in this case, you can look at the block size provided by the subnet mask and then figure out what host range the given host ip is a part of.

    Step 1: Determine the block size given the subnet mask: = block size of 128 - 256 = 128.
    Step 2: Determine that the given host ip address exists within the first block size of the subnet given the "95" which yields a subnet range of -
    Step 3: As Rob42 mentions above, the actual host range of the subnet range determined in step 3 is - after removing the first ip address and last ip address because they are reserved for the network and broadcast addresses respectively.
  • rob42rob42 Member Posts: 423
    vlrk wrote: »
    thanks rob.. it skipped out of my mind.

    You're welcome. Easy thing to forget, but it'll stick now, I'll bet...

    The 'block size' method that Uriah7 explains is an excellent way to learn Subnetting, b.t.w.
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