I don't know with Indy, but in Delphi there are the WinApi.IPHlpApi e WinAPi.IPTypes that are acquired from Project JEDI.   You must enumerate the Interface cards and looks for properties:   Uses WinAPi.IpHlpApi, WinApi.IpTypes; var NumInterfaces: Cardinal; AdapterInfo: array of TIpAdapterInfo; OutBufLen: ULONG; begin GetNumberOfInterfaces(NumInterfaces); SetLength(AdapterInfo, NumInterfaces); OutBufLen := NumInterfaces * SizeOf(TIpAdapterInfo); GetAdaptersInfo(@AdapterInfo[0], OutBufLen); for var i := 0 to NumInterfaces - 1 do begin (* These are the 6 bytes MAC Addresses of Interfaces AdapterInfo[i].Address[0], AdapterInfo[i].Address[1] AdapterInfo[i].Address[2], AdapterInfo[i].Address[3] AdapterInfo[i].Address[4], AdapterInfo[i].Address[5] *) end; end; EDIT: This works only in Windows platforms.