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what is the subnet mask for this hst IP prefix format ? Host IP Address: 183.91.104.16
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220.220.220.0 is an invalid subnet mask.
The subnet mask for the IP address 10.0.0.138 typically depends on the network configuration. In a default Class A configuration, the subnet mask would be 255.0.0.0, which corresponds to a /8 prefix. However, the actual subnet mask can vary based on specific network needs and can be configured to something like 255.255.255.0 (a /24 prefix) or others depending on how the network is structured.
5
Without a subnet mask a client is not able to participate on a network because the network software is unable to determine the network addresses.
It does not require a subnet mask.
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.
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.
To determine the network or subnet address of an IP address
binary ANDing
binary ANDing