using a class B ip with the subnet mask 255.240.0.0

[jjcarranza]

if i have an ip address 172.16.0.0 with the subnet mask 255.240.0.0,

the default subnet mask for a class B ip is 255.255.0.0 , what is the

objective of use a subnetmask 255.240.0.0 ? something like superneting?

[MickPhelps]

It would be more useful as a summarization of the networks 172.16.0.0 through 172.31.0.0 in a single line in your routing table.

Obviously, you wouldn't actually have a "subnet" or flat network with 2**20-2 hosts on it.

Mick.