/// <summary>
/// Check existance Domain in PTR record
/// </summary>
/// <param name="ipAddress">IP address for PTR check</param>
/// <param name="domainName">PTR domain name</param>
/// <exception cref="ArgumentNullException">if domainName or ipAddress is empty/null</exception>
/// <exception cref="ArgumentException">if domainName is invalid</exception>
/// <returns>true if exists and vice versa</returns>
public bool IsDomainPtrRecordExists(IPAddress ipAddress, string domainName)
{
if (string.IsNullOrEmpty(domainName))
{
throw new ArgumentNullException("domainName");
}
if (ipAddress == null)
{
throw new ArgumentNullException("ipAddress");
}
var domain = DomainName.Parse(domainName);
var ptrDomain = _sDnsResolver.ResolvePtr(ipAddress);
return(ptrDomain.Equals(domain));
}