Http error 400 the request hostname is invalid iis

MrWhite

39.7k6 gold badges56 silver badges82 bronze badges

Did you check the binding is IIS? (inetmgr.exe) It may not be registered to accept all hostnames on 8080.

For example, if you set it up for mysite.com:8080 and hit it at localhost:8080, IIS will get the request but not have a hostname binding to match so it rejects.

Outside of that, you should check the IIS logs (C:inetpublogswmsvc#) on the server and see if you are seeing your request. Then you’ll know if its a problem on your client or on the server itself.

answered Jan 28, 2011 at 17:59

FWIW, if you’d like to just allow requests directed to any hostname/ip then you can set your binding like so:

<binding protocol="http" bindingInformation="*:80:*" />

I use this binding so that I can load a VM with IE6 and then debug my application.

EDIT: While using IIS Express to debug, the default location for this option’s config file is

C:Users{User}DocumentsIISExpressconfigapplicationhost.config

This page by Microsoft describes how to set up access to IIS Server Express from other computers on the local network.

In a nutshell:

1) from a command prompt with admin privileges:

netsh http add urlacl url=http://[your ip address]:8181/ user=everyone

2) In Windows Firewall with Advanced Security, create a new inbound rule for port 8181 to allow external connections

3) In applicationhost.config, in the node for your project, add:

<binding protocol="http" bindingInformation="*:8181:[your ip address]" />

Do NOT add (as was suggested in another answer):

<binding protocol="http" bindingInformation="*:8181:*" />

The above wildcard binding broke my access from http://192.168.1.6:8181/

So, I solved this by going to my website in IIS Manager and changing the host name in site bindings from localhost to *. Started working immediately.

answered Aug 10, 2015 at 17:00

Don’t forget to bind to the IPv6 address as well! I was trying to add a site on 127.0.0.1 using localhost and got the bad request/invalid hostname error. When I pinged localhost it resolved to ::1 since IPv6 was enabled so I just had to add the additional binding to fix the issue.

answered Oct 30, 2015 at 21:45

answered Jul 12, 2017 at 22:05

I’m not sure if this was your problem but for anyone that’s trying to access his web application from his machine and having this problem:

Make sure you’re connecting to 127.0.0.1 (a.k.a localhost) and not to your external IP address.

Your URL should be something like http://localhost:8181/ or http://127.0.0.1:8181 and not http://YourExternalIPaddress:8181/.

Additional information:
The reason this works is because your firewall may block your own request. It can be a firewall on your OS and it can be (the usual) your router.

When you connect to your external IP address, you connect to you from the internet, as if you were a stranger (or a hacker).
However when you connect to your localhost, you connect locally as yourself and the block is obviously not needed (& avoided altogether).

answered Jan 26, 2013 at 9:26

answered Jul 28, 2012 at 4:13

I also had this issue, but it was related to AllowedHosts of my application configuration

If it’s a .Net application you should probably have appsettings.json
Have a look of it’s AllowedHosts and try to change it to all-allowed «*»

{
    "Logging": {
        "LogLevel": {
            "Default": "Information",
            "Microsoft": "Warning",
            "Microsoft.Hosting.Lifetime": "Information"
        }
    },
    "AllowedHosts": "*",
}

So in case of incorrect AllowedHosts value, you will also have BarRequest error

answered Jan 17, 2022 at 16:07

robakerrobaker

1,0287 silver badges11 bronze badges

answered Jun 25, 2014 at 14:42

dan9298dan9298

1951 silver badge11 bronze badges

TaranTaran

11.9k3 gold badges39 silver badges46 bronze badges

DudiDudi

3,0291 gold badge25 silver badges23 bronze badges