A default subnet mask gives you classful addressing on octet boundaries. A non-default subnet mask implies that you are subnetting a larger network into several smaller ones.
I really wish to know
255.0.0.0The default subnet mask of a class A network is 255.0.0.0
What is the default subnet mask for an IP address of 198.133.219.4?
255.255.255.0
255.0.0.0
Since this is a class B with the default subnet mask the network would be: 172.32.0.0
The default subnet mask has a standard size. The custom subnet mask allows you to make subnets that are smaller or larger than the default.
255.255.255.0
The default subnet would be 255.0.0.0 (class A)
If this is a default subnet mask, then it would be a class C subnet mask. If you are subnetting a network and this is not the default subnet mask, then it could be either a class A or class B.
255.0.0.0The default subnet mask of a class A network is 255.0.0.0
255.0.0.0
255.255.255.0
Class A default is 255.0.0.0 Class B default is 255.255.0.0 Class C default is 255.255.255.0
The default subnet mask for this address - a class A address - is 255.0.0.0 (same as /8).
subnet mask default gateway address
255.255.255.0
255.0.0.0