I am in a need to search for a certain server on the network

I have found two ways to use to search
a) sqlcmd -L
b) WMI => wbemtest => namespace:root\directory\ldap => QUERYELECT * FROM ds_ms_sql_sqlserver

Both methods return different results

Please elaborate on both methods and also, what other different approaches can be taken to search for sql server(s) on a corporate network?

Thank You Very Much