subnetting

[callmebefore]

Peace upon you brigadiers !

Does it make sense my question?

A host uses the address/mask combination of 192.168.32.99 255.255.128.0. If all subnets of the same class A, B, or C network use that same mask, how many bits are used for the subnet part of the address structure?

[Richard Burts]

192.168 is a class C network and as such subnetting would use bits in the fourth octet. The zero in the fourth octet of the mask indicates that there is not any subnetting and that addressing is a single network.

[balaji.bandi]

I like Keith video that explain better rather in confuse you :

https://www.youtube.com/watch?v=UCoVs1Ri1IA

[Giuseppe Larosa]

Hello @callmebefore ,

>> A host uses the address/mask combination of 192.168.32.99 255.255.128.0. If all subnets of the same class A, B, or C network use that same mask, how many bits are used for the subnet part of the address structure?

This is actually a case of supernetting you have moved the subnet boundary on the left like in route aggregation you have aggregated 128 Class C in one supernet and  you have 17 bits used by the subnet portion and 15 bits used by the host portion.

This was not allowed before the introduction of CIDR Classless Inter Domain Routing.

Hope to help

Giuseppe

[Joseph W. Doherty]

A 9

B 1

C 0 (supernet 7)