DZone
Thanks for visiting DZone today,
Edit Profile
  • Manage Email Subscriptions
  • How to Post to DZone
  • Article Submission Guidelines
Sign Out View Profile
  • Post an Article
  • Manage My Drafts
Over 2 million developers have joined DZone.
Log In / Join
Please enter at least three characters to search
Refcards Trend Reports
Events Video Library
Refcards
Trend Reports

Events

View Events Video Library

Zones

Culture and Methodologies Agile Career Development Methodologies Team Management
Data Engineering AI/ML Big Data Data Databases IoT
Software Design and Architecture Cloud Architecture Containers Integration Microservices Performance Security
Coding Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks
Culture and Methodologies
Agile Career Development Methodologies Team Management
Data Engineering
AI/ML Big Data Data Databases IoT
Software Design and Architecture
Cloud Architecture Containers Integration Microservices Performance Security
Coding
Frameworks Java JavaScript Languages Tools
Testing, Deployment, and Maintenance
Deployment DevOps and CI/CD Maintenance Monitoring and Observability Testing, Tools, and Frameworks

Because the DevOps movement has redefined engineering responsibilities, SREs now have to become stewards of observability strategy.

Apache Cassandra combines the benefits of major NoSQL databases to support data management needs not covered by traditional RDBMS vendors.

The software you build is only as secure as the code that powers it. Learn how malicious code creeps into your software supply chain.

Generative AI has transformed nearly every industry. How can you leverage GenAI to improve your productivity and efficiency?

Related

  • GDPR Compliance With .NET: Securing Data the Right Way
  • How to Enhance the Performance of .NET Core Applications for Large Responses
  • Zero to AI Hero, Part 3: Unleashing the Power of Agents in Semantic Kernel
  • Developing Minimal APIs Quickly With Open Source ASP.NET Core

Trending

  • How to Use AWS Aurora Database for a Retail Point of Sale (POS) Transaction System
  • Introduction to Retrieval Augmented Generation (RAG)
  • Security by Design: Building Full-Stack Applications With DevSecOps
  • IoT and Cybersecurity: Addressing Data Privacy and Security Challenges
  1. DZone
  2. Coding
  3. Frameworks
  4. ASP.NET: Converting X-Forwarded-For To REMOTE_HOST

ASP.NET: Converting X-Forwarded-For To REMOTE_HOST

By 
Jon Davis user avatar
Jon Davis
·
Nov. 04, 10 · News
Likes (0)
Comment
Save
Tweet
Share
15.8K Views

Join the DZone community and get the full member experience.

Join For Free

Just keeping notes here. If you’re using IIS Mod Rewrite or if you’re running a reverse proxy or a non-transparent load balancer, you may find the request URL server variable mismatching and the REMOTE_ADDR server variable coming back as the IP address of the proxy server or as the load balancer IP. This is no good, because all of the user’s IP address information is lost. Well, almost lost. What should happen is the the reverse proxy is supposed to add an X-Forwarded-For HTTP header in the request headers containing the user’s IP address, as well as X-Original-URL. This can then be read back by the web server.

The problem is, even with X-Forwarded-For being passed in to the web server, REMOTE_ADDR is still wrong.

I’m looking for the easiest path to just fix this once and for all without delving into web application code. So I’m playing with this simple global.asax tweak to fix this. I haven’t fully tested this yet so, again, just taking notes here ..

void Application_BeginRequest(object sender, EventArgs e)
{
var ss = Request.ServerVariables["SERVER_SOFTWARE"];
if (!string.IsNullOrEmpty(ss) && ss.Contains("Microsoft-IIS")) // doesn't work w/ Cassini
{
string SourceIP = String.IsNullOrEmpty(Request.ServerVariables["HTTP_X_FORWARDED_FOR"])
? Request.ServerVariables["REMOTE_ADDR"]
: Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
Request.ServerVariables.Set("REMOTE_ADDR", SourceIP);
Request.ServerVariables.Set("REMOTE_HOST", SourceIP);

string OrigUrl = Request.ServerVariables["HTTP_X_ORIGINAL_URL"];
if (!string.IsNullOrEmpty(OrigUrl))
{
var url = new Uri(Request.Url, OrigUrl);
Request.ServerVariables.Set("SERVER_NAME", url.Host);
Request.ServerVariables.Set("SERVER_PORT", url.Port.ToString());
}
}
}
ASP.NET

Published at DZone with permission of Jon Davis, DZone MVB. See the original article here.

Opinions expressed by DZone contributors are their own.

Related

  • GDPR Compliance With .NET: Securing Data the Right Way
  • How to Enhance the Performance of .NET Core Applications for Large Responses
  • Zero to AI Hero, Part 3: Unleashing the Power of Agents in Semantic Kernel
  • Developing Minimal APIs Quickly With Open Source ASP.NET Core

Partner Resources

×

Comments
Oops! Something Went Wrong

The likes didn't load as expected. Please refresh the page and try again.

ABOUT US

  • About DZone
  • Support and feedback
  • Community research
  • Sitemap

ADVERTISE

  • Advertise with DZone

CONTRIBUTE ON DZONE

  • Article Submission Guidelines
  • Become a Contributor
  • Core Program
  • Visit the Writers' Zone

LEGAL

  • Terms of Service
  • Privacy Policy

CONTACT US

  • 3343 Perimeter Hill Drive
  • Suite 100
  • Nashville, TN 37211
  • support@dzone.com

Let's be friends:

Likes
There are no likes...yet! 👀
Be the first to like this post!
It looks like you're not logged in.
Sign in to see who liked this post!