Exposing localhost to the internet via tunneling (using ngrok): HTTP error 400: bad request; invalid hostname - asp.net

Question

From previous versions of the question, there is this: Browse website with ip address rather than localhost, which outlines pretty much what I've done so far...I've got the local IP working. Then I found ngrok, and apparently I don't need to connect via the IP.
What I am trying to do is expose my website running on localhost to the internet. I found a tool that will do this: ngrok.
Running the website in visual studio, the website starts up on localhost/port#. I run the command "ngrok http port#" in the command line. Everything seems to start up fine. I generate a couple of URLs, and the ngrok inspection url (localhost:4040) works.
The only problem is that when I go to the generated URLs, I get an HTTP error 400: bad request invalid hostname. This is a different error than when I run "ngrok http wrongport#", which is a host not found error...so I think something good is happening. I just can't tell what...
Is there a step I am missing in exposing my site to the internet via the tunneling service? If there is, I can't find it in the ngrok documentation.

Answer 1

Troubleshot this issue with ngrok. In the words of inconshrevable, some applications get angry when they see a different host header than expected.
Running the following command should fix the problem:
ngrok http [port] --host-header="localhost:[port]"
Depending on the version, you may also want to try:
ngrok http [port] --host-header="localhost:[port]"

Answer 2

Following command will fix the issue
ngrok http -host-header=localhost 8080

Answer 3

This didn't work for me.
you could do the following:
For IIS Express
In VS 2015:
Go to the .vs\config\applicationhost.config folder in your project
In VS 2013 and earlier:
Go to %USERPROFILE%\My Documents\IISExpress\config\applicationhost.config
Find the binding that says:
<binding protocol="http" bindingInformation="*:5219:localhost" />
For me it was a project running on port 5219
change it to
<binding protocol="http" bindingInformation="*:5219:" />
IIS Express will now accept all incoming connections on that port.
Disadvantage: you need to run IIS Express as admin.
or you could rewrite the host header in Ngrok:
ngrok.exe http -host-header=rewrite localhost:5219

Answer 4

For https this works:
ngrok http https://localhost:<PORT> --host-header="localhost:<PORT>"

Answer 5

UPDATED COMMAND FOR LATEST VERSION
Tested with: (Windows) (ngrok v3.0.5)
Use -- instead of -
ngrok http --host-header=localhost 8080

Answer 6

The simplest thing for me was using iisexpress-proxy + ngrok.
First I install iisexpress-proxy globally with npm
npm install -g iisexpress-proxy
Then I proxy my localhost with it. Say for instance my site is running on 3003.
iisexpress-proxy 3003 to 12345 where 12345 is the new http port I want to proxy to.
Then I can run ngrok on it.
./ngrok.exe http 12345
It just works! 😃
But I think it works only with http. Right now I don't use https to test, but even if it works, usually it's a lot of work as always.

Answer 7

For https this works:
ngrok http https://localhost:<PORT> --host-header="localhost:<PORT>"

Answer 8

Try with different locations from the Global infrastructure > Locations
ngrok http -region eu 8080
You can make a request and view any traffic passing through your tunnel using the ngrok traffic inspector at http://localhost:4040.
OR in command line
ngrok http -region eu 8080 --log=stdout
If one region fails then try with another.
ngrok runs tunnel servers in datacenters around the world. The location of the datacenter within a given region may change without notice (e.g. the European servers may move from Frankfurt to London).
us - United States (Ohio)
eu - Europe (Frankfurt)
ap - Asia/Pacific (Singapore)
au - Australia (Sydney)
sa - South America (Sao Paulo)
jp - Japan (Tokyo)
in - India (Mumbai)

Answer 9

First open ngrok configuration YAML file, run from terminal:
ngrok config edit
Example of yaml for localhost setup (client & server):
version: "2"
authtoken: {YOUR_AUTH_TOKEN_FROM_NGROK_WEBSITE}
tunnels:
client:
addr: 3000
proto: http
host_header: localhost
server:
addr: 4000
proto: http
host_header: localhost
Save the config file based on your client and server ports and run the following command:
ngrok start --all
This will make ngrok open a tunnel for all the configurations declared in the yaml file

Answer 10

Had IIS Express .net web API, had installed NGROK in docker (windows as a host)
Had "Bad Request" error, the next command worked for me:
docker run -it -e NGROK_AUTHTOKEN=<token> ngrok/ngrok --host-header=localhost:21852 http host.docker.internal:21852
As I understood later, --host-header needed because IIS Express refuses all requests from outside (must be "localhost:port
"), host.docker.internal I've used instead of localhost, because NGROK was running inside docker, while IIS Express was running on a windows host.

Answer 11

I had the same issue and used the following solution:
Make sure your application binding in your IIS is set to All Unassigned IP address
Run ngrok HTTP 127.0.0.1:173 --region=eu --hostname=yourcustomdomain.eu.ngrok.io
That's it. Works perfectly. This solution is also for paid pro accounts

Answer 12

Steps.
Run command on your console from ngrok.exe directory . ngrok http
port i.e ngrok http 80 https://www.screencast.com/t/oyuEPlR6Z Set
Ngrok url to your app .
It will create a tunnel to your application.
Thanks .