Problem with starting .net core application. Unable to start Kestrel on port 80

Question

When i try to start an application on port 80 i get error.

I've tried to start this app on different port and it worked but when i choose port <1100 it have some problems.

I use this command:

dotnet appname.dll --urls="http://localhost:80"

And the error looks like this:

Microsoft.AspNetCore.Server.Kestrel[0] Unable to bind to http://localhost:80 on the IPv4 loopback interface: 'Permission denied'. warn: Microsoft.AspNetCore.Server.Kestrel[0] Unable to bind to http://localhost:80 on the IPv6 loopback interface: 'Permission denied'. crit: Microsoft.AspNetCore.Server.Kestrel[0] Unable to start Kestrel. System.IO.IOException: Failed to bind to address http://localhost:80. ---> System.AggregateException: One or more errors occurred. (Permission denied) (Permission denied) ---> System.Net.Sockets.SocketException: Permission denied at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, String callerName) at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.Sockets.Socket.Bind(EndPoint localEP) at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransport.BindAsync() at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<>c__DisplayClass21_01.<<StartAsync>g__OnBind|0>d.MoveNext() --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.LocalhostListenOptions.BindAsync(AddressBindContext context) --- End of inner exception stack trace --- --- End of inner exception stack trace --- at Microsoft.AspNetCore.Server.Kestrel.Core.LocalhostListenOptions.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func2 createBinding) at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)

Unhandled Exception: System.IO.IOException: Failed to bind to address http://localhost:80. ---> System.AggregateException: One or more errors occurred. (Permission denied) (Permission denied) ---> System.Net.Sockets.SocketException: Permission denied at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, String callerName) at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.Sockets.Socket.Bind(EndPoint localEP) at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransport.BindAsync() v at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<>c__DisplayClass21_01.<<StartAsync>g__OnBind|0>d.MoveNext() --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.LocalhostListenOptions.BindAsync(AddressBindContext context) --- End of inner exception stack trace --- --- End of inner exception stack trace --- at Microsoft.AspNetCore.Server.Kestrel.Core.LocalhostListenOptions.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func2 createBinding) at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken) at Microsoft.AspNetCore.Hosting.Internal.WebHost.StartAsync(CancellationToken cancellationToken) at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String shutdownMessage) at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token) at Microsoft.AspNetCore.Hosting.WebHostExtensions.Run(IWebHost host)

Answer 1

The solution to this problem was @JonasMH comment. "Have you tried running in an administrator console?" It worked for me!