Getting domain Name in xamarin.mac

hi,

i am not able to fetch the domain name in xamarin as i would in windows. please help.
i tried the below options with no luck:

var domainname = new System.Text.StringBuilder(256);
Mono.Unix.Native.Syscall.getdomainname(domainname,
(ulong)domainname.Capacity);

string domainname=System.Net.NetworkInformation.IPGlobalProperties.GetIPGlobalProperties().DomainName;