Public Shared ReadOnly Property Anonymous As NetworkCredential

public static NetworkCredential Anonymous {get;}

Guid iid = Guid.NewGuid();
using (RpcServerApi server = new RpcServerApi(iid))
{
    server.AddProtocol(RpcProtseq.ncacn_np, @"\pipe\testpipename", 5);
    server.AddAuthentication(RpcAuthentication.RPC_C_AUTHN_NONE);
    server.StartListening();
    server.OnExecute +=
        delegate(IRpcClientInfo client, byte[] arg)
        {
            Assert.AreEqual(0, arg.Length);
            Assert.AreEqual(RpcAuthentication.RPC_C_AUTHN_NONE, client.AuthenticationLevel);
            Assert.AreEqual(RpcProtectionLevel.RPC_C_PROTECT_LEVEL_NONE, client.ProtectionLevel);
            Assert.AreEqual(RpcProtoseqType.NMP, client.ProtocolType);
            Assert.AreEqual(new byte[0], client.ClientAddress);
            Assert.AreEqual(0, client.ClientPid.ToInt32());
            Assert.AreEqual(null, client.ClientPrincipalName);
            Assert.AreEqual(System.Security.Principal.WindowsIdentity.GetAnonymous().Name, client.ClientUser.Name);
            Assert.AreEqual(true, client.IsClientLocal);
            Assert.AreEqual(false, client.IsAuthenticated);
            Assert.AreEqual(false, client.IsImpersonating);

            bool failed = false;
            try { client.Impersonate().Dispose(); }
            catch (UnauthorizedAccessException) { failed = true; }
            Assert.AreEqual(true, failed);
            return arg;
        };

    using (RpcClientApi client = new RpcClientApi(iid, RpcProtseq.ncacn_np, null, @"\pipe\testpipename"))
    {
        client.AuthenticateAs(RpcClientApi.Anonymous);
        client.Execute(new byte[0]);
    }
}

Dim iid As Guid = Guid.NewGuid()
Using server As New RpcServerApi(iid)
    server.AddProtocol(RpcProtseq.ncacn_np, "\pipe\testpipename", 5)
    server.AddAuthentication(RpcAuthentication.RPC_C_AUTHN_NONE)
    server.StartListening()
    server.OnExecute += Function(client As IRpcClientInfo, arg As Byte()) Do
        Assert.AreEqual(0, arg.Length)
        Assert.AreEqual(RpcAuthentication.RPC_C_AUTHN_NONE, client.AuthenticationLevel)
        Assert.AreEqual(RpcProtectionLevel.RPC_C_PROTECT_LEVEL_NONE, client.ProtectionLevel)
        Assert.AreEqual(RpcProtoseqType.NMP, client.ProtocolType)
        Assert.AreEqual(New Byte(0) {}, client.ClientAddress)
        Assert.AreEqual(0, client.ClientPid.ToInt32())
        Assert.AreEqual(Nothing, client.ClientPrincipalName)
        Assert.AreEqual(System.Security.Principal.WindowsIdentity.GetAnonymous().Name, client.ClientUser.Name)
        Assert.AreEqual(True, client.IsClientLocal)
        Assert.AreEqual(False, client.IsAuthenticated)
        Assert.AreEqual(False, client.IsImpersonating)

        Dim failed As Boolean = False
        Try
            client.Impersonate().Dispose()
        Catch generatedExceptionName As UnauthorizedAccessException
            failed = True
        End Try
        Assert.AreEqual(True, failed)
        Return arg
    End Function

    Using client As New RpcClientApi(iid, RpcProtseq.ncacn_np, Nothing, "\pipe\testpipename")
        client.AuthenticateAs(RpcClientApi.Anonymous)
        client.Execute(New Byte(0) {})
    End Using
End Using