OPC Studio User's Guide and Reference
HostNamesString Property (UACreateCertificateArguments)



OpcLabs.EasyOpcUA Assembly > OpcLabs.EasyOpc.UA.Application Namespace > UACreateCertificateArguments Class : HostNamesString Property
A comma-separated list of host names for the application instance.
Syntax
'Declaration
 
<DataMemberAttribute()>
<NotNullAttribute()>
Public Property HostNamesString As String
'Usage
 
Dim instance As UACreateCertificateArguments
Dim value As String
 
instance.HostNamesString = value
 
value = instance.HostNamesString
[DataMember()]
[NotNull()]
public string HostNamesString {get; set;}
[DataMember()]
[NotNull()]
public:
property String^ HostNamesString {
   String^ get();
   void set (    String^ value);
}

Property Value

The value of this property cannot be null (Nothing in Visual Basic).

The default value of this property is "" (String.Empty).

Remarks

This string is a comma-separated list of host names in the HostNames collection.

Host names are only relevant for servers.

When no host names are specified, the component uses default host names instead. For server applications, the default host names consist of known DNS and NetBIOS names and IPv4 and IPv6 addresses of the local host. For applications that are not servers, the default host names are empty.

The host names come into play in following situations:

From UA-.NETStandard comments: "These list the alternate host names (via firewalls, multiple NICs etc.) that can be used to communicate with the server. The URL used by the client when calling FindServers/GetEndpoints or CreateSession will be used to filter the list of endpoints returned by checking for alternate host names that match the domain in the URL provided by the client.
Note that any additional domains should be listed in the server's certificate. If they are left out the client make refuse to connect because it has no way to know if the alternate domain was authorized by the server administrator."

From OPC UA specification: "Servers shall specify a partial or a fully qualified dNSName or a static IPAddress which identifies the machine where the application Instance runs. Additional dNSNames may be specified if the machine has multiple names."

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

See Also