CODEWITHSUNDEEP
iis-expresspostman
Mike Casas
Mike Casas

Reputation: 813

ASP.NET Unauthorized in Postman using IIS Express, but works in Chrome

I am trying to test an ASP.NET Web Api locally using IIS Express. When I use Chrome and hit the url (localhost:5000/api/test, for example) the json displays fine, but when using Postman I keep getting unauthorized 401.2 when hitting the same url. The api controller has Anonymous access on the route.

On the error message, one of the likely causes is:

Integrated authentication is enabled and the request was sent through a proxy that changed the authentication headers before they reach the Web server.

Is Postman somehow changing the headers?

Upvotes: 5

Views: 7680

Answers (3)

Steven
Steven

Reputation: 118

I have a localhost WebAPI site up with IIS Express (HTTPS). Postman started to respond as expected to GETs and POSTs after I changed (in Postman) File --> Settings --> Proxy

  • to: "Use the system proxy"
  • and turning on: "Respect HTTP_PROXY ...".

I had earlier set up a custom proxy that wasn't working with HTTPS.

enter image description here

Upvotes: 0

XavierAM
XavierAM

Reputation: 1775

[2019 Update]

Got the same issue, I couldn't debug an ASP Core 2.1 API using Postman when running on the local machine using IIS Express. I kept on having "Could not get any response" despite it was working fine on a browser.

Following troubleshooting steps explained here PostmanLabs Github, I noticed into Postman console that this was coming from a certificate issue.

Disabling SSL Verification from Postman Settings > General allowed the request to pass through.

Postman Settings

Upvotes: 10

Vladislav Vitalyev
Vladislav Vitalyev

Reputation: 168

Looks like it's your proxy.

I haven't found the proxy setting in postman. So I deleted postman for Win and installed postman for Chrome. Possibly Postman gets the environment from Chrome.

Anyway the resolution is to use Postman for Chrome instead of Postman for Win.

Upvotes: 6

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