Skip to main content

Variable-Length Subnet Masks

More
13 years 2 months ago #36084 by ping
Hi,

I was reading about variable length subnet masks on one of the presentations from one site and I came across this particular site which contained some statements I was unable to understand.

The site was explaining about various possible VLSM assignments.

The slide had following content.
I would be very thankful if someone could explain how these assignments are carried out.


Title: Use Of Address Space (Start With 16 Bits Of Host Suffix)
    One possible VLSM assignment (92.9% of addresses used)
    11 networks of 2046 hosts each
    24 networks of 254 hosts each
    256 networks of 126 hosts each

    Another possible VLSM assignment (93.1% of addresses
    used)
    9 networks of 2046 hosts each
    2 networks of 1022 hosts each
    40 networks of 510 hosts each
    160 networks of 126 hosts each


Thanks...

Ping

The greatest pleasure in life is doing what people say you can not do..!!
More
13 years 2 months ago #36086 by Chojin
VLSM is a word for not using classfull subnets.

the 10.0.0.0/8 is a classful subnet, when using VLSM (that is variable length subnet masks) you can for example split the 10.0.0.0/8 up in multiple networks.


10.1.0.0/16
10.2.0.0/16
10.3.0.0/24
10.3.1.0/24

etc. This way you can make your networks smaller (or larger when supernetting) and adjust it to your needs.

Hope this sheds a bit of light :-)

CCNA / CCNP / CCNA - Security / CCIP / Prince2 / Checkpoint CCSA
More
13 years 2 months ago #36088 by rizin
Hi Ping,

On Which Class Address they want to apply those VLSM e.g A, B, or C, so that you will able to know the answer precisely.

Rizin

Known is a drop, unknown is an Ocean
More
13 years 2 months ago #36089 by ping
Thank You Chojin, the issues is clear now..

The greatest pleasure in life is doing what people say you can not do..!!
More
13 years 2 months ago #36090 by ping
rizin, in the example I was reading it was referring to class B addresses..

The greatest pleasure in life is doing what people say you can not do..!!
More
13 years 2 months ago #36095 by rizin
thanks ping and it is sounding great that your issues had got cleared.

Known is a drop, unknown is an Ocean
Time to create page: 0.155 seconds