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.
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.
255.255.255.0
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
255.255.255.0
The default subnet mask would be 255.255.0.0 for a class B address.
Since this is a Class C address, the default network mask is 255.255.255.0.Since this is a Class C address, the default network mask is 255.255.255.0.Since this is a Class C address, the default network mask is 255.255.255.0.Since this is a Class C address, the default network mask 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
It depends on whether you are subnetting or not. If not, the default subnet mask would be 255.255.255.0
255.0.0.0
255.0.0.0