Failed to bind to address (already in use) error with Visual Studio Mac API

Question

I'm attempting to create a Web API via .Net Core. I'm just using the boilerplate ValuesController as a Hello World. When I run the project, I get the following error:

System.IO.IOException: "Failed to bind to address https://127.0.0.1:5001: address already in use." ---> System.Exception {Microsoft.AspNetCore.Connections.AddressInUseException}: "Address already in use" ---> System.Exception {System.Net.Sockets.SocketException}: "Address already in use"
  at at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, String callerName)\n   at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)\n   at System.Net.Sockets.Socket.Bind(EndPoint localEP)\n   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransport.BindAsync()
  --- End of inner exception stack trace ---
  at at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransport.BindAsync()\n   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<>c__DisplayClass22_0`1.<<StartAsync>g__OnBind|0>d.MoveNext()\n--- End of stack trace from previous location where exception was thrown ---\n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context)
  --- End of inner exception stack trace ---
  at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context)\n   at Microsoft.AspNetCore.Server.Kestrel.Core.LocalhostListenOptions.BindAsync(AddressBindContext context)\n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context)\n   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func`2 createBinding)\n   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)\n   at Microsoft.AspNetCore.Hosting.Internal.WebHost.StartAsync(CancellationToken cancellationToken)\n   at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String shutdownMessage)\n   at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token)\n   at Microsoft.AspNetCore.Hosting.WebHostExtensions.Run(IWebHost host)\n   at Sysmex.Unity.Interfaces.WebAPI.Program.Main(String[] args) in /Users/mharrison/Developer/unity-interfaces/Sysmex.Unity.Interfaces.WebAPI/Sysmex.Unity.Interfaces.WebAPI/Program.cs:17

I'm assuming this is just a simple setting problem, but I haven't been able to find anything while Googling. Is there anything that I need to set to allow me to debug the project on Mac OS?

While this may not be a solution to the underlying problem, a quick fix to get it working again is to execute `kill -9 $(lsof -i:PORT -t) 2> /dev/null`, where PORT is the port that is claimed to be already in use (e.g., 5001) — Ash, May 31 '19 at 04:20

score 40 · Answer 1 · answered Dec 14 '20 at 03:47

40

Sure you can change the port every time you get that error or even restart your computer, here is the correct way to go about this

Find what is running on that port and kill the process

Terminal on mac

find the process number

lsof -i: <port number> eg lsof -i:5001

Then kill the process number

kill -9 <process number> eg - kill -9 1600

answered Dec 14 '20 at 03:47

BitcoinKing

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I know the answer is specific to MAC but also works fine on Linux as well. (I know MAC is Linux only but just put it here if someone doesn't know that :) ) – Prashant Abdare Mar 05 '22 at 07:46
On UBUNTU: `sudo kill -9 'sudo lsof -t -i:5001'` – Reza Taba Mar 13 '22 at 14:23

score 17 · Answer 2 · answered Feb 27 '19 at 12:01

17

I know this is late answer. But it may be helpful to somebody.

There seems a bug with MAC Visual Studio, it always goes https://127.0.0.1/5001.

If you right click on your project, select options. Then Project Options Dialog will appear. On the left pane, goto Run->Configurations->Default, then on the right pane select ASP.Net Core tab. There is App URL which is being used by default. Change it to your needs.

answered Feb 27 '19 at 12:01

Amit

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I changed it but still it doesn't work when I change it and then run it it again gives an error and when I check the url is again https://localhost:5001http://localhost:5000 – Nairi Areg Hatspanyan Jun 18 '20 at 15:04
@Amit, you saved my day. Works for me! Thanks a lot :) – RuntimeError Oct 27 '20 at 16:17
I've changed mine to be different ports in the launchSettings.json and in webBuilder.UseUrls and it STILL uses different ports than what I put in there. – ScubaSteve Mar 22 '21 at 18:24

score 14 · Answer 3 · answered Sep 15 '20 at 10:56

14

Assuming that you are using default port:

this usually happens when a process gets corrupt and is disconnected from visual studio.

If you are on mac, open activity monitor and kill the process by name "dotnet"

If you are using a non standard port: then you need to change the port number to an available one. There is a solution from Amit on this thread, use that to change the port.

answered Sep 15 '20 at 10:56

Kalpesh Popat

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most simple answer and solution. I had two stale dotnet processes when this happened to me. should have far more upvotes. – MSicc Mar 26 '22 at 06:37

Celal Yildirim · Answer 4 · 2018-10-04T19:51:44.373

The port 5001 has already used in your system. Change port number to 5002 or whatever you want.

You can add port number with .UseUrls into CreateWebHostBuilder

  public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseUrls("http://localhost:5002")
            .UseStartup<Startup>();

Or if you use visual studio code, just replace args section in .vscode -> launch.json.

"args": ["urls=http://localhost:5002"]

score 6 · Answer 5 · answered Nov 03 '21 at 13:59

For those who come here because they updated to MacOs Monterey. It has services listening by default on ports 5000 and 7000.

If you are blocked on those ports, running lsof -i tcp:5000 (or 7000) will show something like:

COMMAND   PID USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
ControlCe 371 me   17u  IPv4 0xad81aeb96e1d0669      0t0  TCP *:commplex-main (LISTEN)
ControlCe 371 me   18u  IPv6 0xad81aeb9709a5f91      0t0  TCP *:commplex-main (LISTEN)

For now, you can manually stop the OS from listening on these ports by unchecking AirPlay Receiver in the Apple menu -> System Preferences -> Sharing section.

https://developer.apple.com/forums/thread/682332

Thanks, this answer finally helped me! – Lennert Feb 21 '22 at 08:44 — Lennert, Feb 21 '22 at 08:44

Tony Dong · Answer 6 · 2021-01-05T23:12:34.703

5

The port 5001 has already used in your system.

Windows, use task manager to kill the processes "dotnet core host"

Mac, force quit 'dotnet' in Activity Monitor app

edited Jan 05 '21 at 23:12

answered Oct 08 '19 at 19:12

Tony Dong

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2

you would force quit 'dotnet' in Activity Monitor app for Mac – umutesen Jan 03 '21 at 22:32

score 5 · Answer 7 · answered Jun 15 '21 at 07:54

5

If you are on Mac, you can find the process running on a port with lsof -i tcp:<PORT>.

To kill the process running on a port, you may try npx kill-port <PORT>

answered Jun 15 '21 at 07:54

Irshu

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score 2 · Answer 8 · answered Oct 08 '20 at 16:41

2

Got a similar Error on my project on port 5002 on Visual studio for MAC 2019, restarting Visual studio did nothing.

i shutdown the machine and relaunched

it's a safer solution i think.

answered Oct 08 '20 at 16:41

Flywings

72
4

score 2 · Answer 9 · answered Aug 28 '21 at 19:16

It seems there is a bug in Visual Studio for Mac. Here is a solution to fix it manually:

1- Open "Run" menu from the top -> "Run with" -> "Custom Configuration". Then go to "ASP.NET Core" tab and copy the "App Url" value. (It's your App's correct port)

2- Now you should paste it inside your project option default run config: in Solution panel, right click on your project and click on "options" -> "Run" -> "Configuration" -> "Default". Then go to "ASP.NET Core" tab and paste the copied value in App Url box.

Now run your project.

score 1 · Answer 10 · answered Jul 02 '19 at 20:33

I was able to at least temporarily solve this issue by implementing a workaround provided by Bill Boga on his site here: https://www.billbogaiv.com/posts/setting-aspnet-host-address-in-net-core-2

The key for my project was to add .UseUrls(urls: "http://localhost:10000") in the BuildWebHost function. Like so:

using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using OrchardCore.Logging;
using OrchardCore.Modules;

namespace ShiftBrandSite
{
    public class Program
    {
        public static void Main(string[] args)
        {
            BuildWebHost(args).Run();
        }

        public static IWebHost BuildWebHost(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseNLogWeb()
                .UseStartup<Startup>()
                .UseUrls(urls: "http://localhost:10000") // <-- localhost urls
                .Build();
    }
}

Hope this helps!

score 0 · Answer 11 · answered Nov 06 '21 at 06:56

0

To complement Amit's answer: Option to change port setting while debugging an ASP.NET Core project in Visual Studio 2019 is as below:

Go to Project Properties > Deubg tab > Web Server Settings > App URL

answered Nov 06 '21 at 06:56

RBT

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score 0 · Answer 12 · answered Jan 21 '22 at 09:06

0

My solution was to restart my mac, then it was all good again.

I did not try to kill dotnet from activity monitor but if it will happen again i will give it a try.

answered Jan 21 '22 at 09:06

miloth

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12

score 0 · Answer 13 · answered Mar 13 '22 at 14:29

0

Linux Ubuntu Solution:

Just kill the process/port

sudo kill -9 'sudo lsof -t -i:5001'

Might work on MAC as well not sure.

answered Mar 13 '22 at 14:29

Reza Taba

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Failed to bind to address (already in use) error with Visual Studio Mac API

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