tricky vlsm question

DANMOH009

I got the following practice question whilst revising and found it extremely a hard, wanted to know if there were any quik ways of doing this.


Network Address = 87.6.0.0
Mask/Prefix = 15


Subnet A
8690

Subnet B
37134


Subnet C
18183


Subnet D
8122


Subnet E
2

Now i was suppose to work out the vlsm network. i started with the highest which is subnet b and i know subnet b needs 65,536 hosts which will give it a prefix of /16 so the answer for subnet b will be 87.6.0.0/16

now this is the tricky part, is there any easy way of me finding out where the next network starts????

i know i have to count up 65,536 hosts, but is there a quick way to do it??


Thanks

Dan

Mutata

The way I usually do this (now I could be wrong because i'm just working through this again myself) is.

87.6.0.0 /16 = 87.6.0.0 255.255.0.0

Last addy (Broadcast) is 87.6.255.255. After that would be the start of your next subnet.

That would make it 87.7.0.0

Anyone with more experience is more than welcome to chime in here on faster ways, I definitely am no expert.