You still haven't actually explained what the line of code that is giving you the messages is trying to do. The error message says:
Please use IPAddress.Equals method to perform comparisons.
Are you performing a comparison? If not the you wouldn't use Equals. Have you read the documentation for the IPAddress.Address property? Why is that not the obvious next step? That documentation says:
This property is obsolete. Use GetAddressBytes.
and kindly provides a link to the documentation for that property. The BitConverter class, which you're already using, can convert those Bytes to an Integer.