Invoke .NET Core 3.1 gRPC service from .NET 4.8 client

[Christian Havel]

Hi,

I started to play around with gRPC. I have a very simple gRPC service in .NET Core 3.1.

Then I wrote a .NET Core 3.1 client. Both applications are running on the same machine.

Everything works fine.

Now I try to connect my gRPC server from a .NET Framework 4.8 client (Windows Forms), that fails with the following exception:

I create the channel on the client like this:

var channel = new Channel($"http://{ip}:{Port}", ChannelCredentials.Insecure);

 _serviceClient = new BridgeService.BridgeServiceClient(channel);

var request = new HelloRequest {Name = "Franz"};

var reply = _serviceClient.SayHello(request);

This is the server side:

var credentials = ServerCredentials.Insecure;

var hostName = Dns.GetHostName();

 _port = new ServerPort(hostName, Port, credentials);

_rpcServer = new Server

{

                Services = {BridgeService.BindService(new BridgeServiceImpl())},

                Ports = { _port }

 };

_rpcServer.Start();

Any idea what is missing?

Thanks,

Christian

[Christian Havel]

Hi,

I would like to add the information, that the gRPC server is a console application, not a ASP.NET Core application.

Christian

[Jan Tattermusch]

I'd try to specify the channel target as "a.b.c.d:3280" without the "http://" prefix. From the error it looks like the URL is being interpreted as a DNS name (rather than an IP).

https://github.com/grpc/grpc/blob/master/doc/naming.md