c# - How do I get client IP address in ASP.NET CORE?

The API has been updated. Not sure when it changed but according to Damien Edwards in late December, you can now do this:

var remoteIpAddress = request.HttpContext.Connection.RemoteIpAddress; 

In project.json add a dependency to:

"Microsoft.AspNetCore.HttpOverrides": "2.2.0" 

In Startup.cs, in the Configure() method add:

app.UseForwardedHeaders(new ForwardedHeadersOptions {     ForwardedHeaders = ForwardedHeaders.XForwardedFor |     ForwardedHeaders.XForwardedProto });   

And, of course:

using Microsoft.AspNetCore.HttpOverrides; 

Then, I could get the ip by using:

Request.HttpContext.Connection.RemoteIpAddress 

In my case, when debugging in VS I got always IpV6 localhost, but when deployed on an IIS I got always the remote IP.

Some useful links: How do I get client IP address in ASP.NET CORE? and RemoteIpAddress is always null

The ::1 is maybe because of:

Connections termination at IIS, which then forwards to Kestrel, the v.next web server, so connections to the web server are indeed from localhost. (https://stackoverflow.com/a/35442401/5326387)

Edit 12/2020: Thanks to SolidSnake: as of Dec 2020 the latest version is 2.2.0

Edit 06/2021: Thanks to Hakan Fıstık: In .NET 5 the namespace is Microsoft.AspNetCore.Builder

Some fallback logic can be added to handle the presence of a Load Balancer.

Also, through inspection, the X-Forwarded-For header happens to be set anyway even without a Load Balancer (possibly because of additional Kestrel layer?):

public string GetRequestIP(bool tryUseXForwardHeader = true) {     string ip = null;      // todo support new "Forwarded" header (2014) https://en.wikipedia.org/wiki/X-Forwarded-For      // X-Forwarded-For (csv list):  Using the First entry in the list seems to work     // for 99% of cases however it has been suggested that a better (although tedious)     // approach might be to read each IP from right to left and use the first public IP.     // http://stackoverflow.com/a/43554000/538763     //     if (tryUseXForwardHeader)         ip = GetHeaderValueAs<string>("X-Forwarded-For").SplitCsv().FirstOrDefault();      // RemoteIpAddress is always null in DNX RC1 Update1 (bug).     if (ip.IsNullOrWhitespace() && _httpContextAccessor.HttpContext?.Connection?.RemoteIpAddress != null)         ip = _httpContextAccessor.HttpContext.Connection.RemoteIpAddress.ToString();      if (ip.IsNullOrWhitespace())         ip = GetHeaderValueAs<string>("REMOTE_ADDR");      // _httpContextAccessor.HttpContext?.Request?.Host this is the local host.      if (ip.IsNullOrWhitespace())         throw new Exception("Unable to determine caller's IP.");      return ip; }  public T GetHeaderValueAs<T>(string headerName) {     StringValues values;      if (_httpContextAccessor.HttpContext?.Request?.Headers?.TryGetValue(headerName, out values) ?? false)     {         string rawValues = values.ToString();   // writes out as Csv when there are multiple.          if (!rawValues.IsNullOrWhitespace())             return (T)Convert.ChangeType(values.ToString(), typeof(T));     }     return default(T); }  public static List<string> SplitCsv(this string csvList, bool nullOrWhitespaceInputReturnsNull = false) {     if (string.IsNullOrWhiteSpace(csvList))         return nullOrWhitespaceInputReturnsNull ? null : new List<string>();      return csvList         .TrimEnd(',')         .Split(',')         .AsEnumerable<string>()         .Select(s => s.Trim())         .ToList(); }  public static bool IsNullOrWhitespace(this string s) {     return String.IsNullOrWhiteSpace(s); } 

Assumes _httpContextAccessor was provided through DI.

You can use the IHttpConnectionFeature for getting this information.

var remoteIpAddress = httpContext.GetFeature<IHttpConnectionFeature>()?.RemoteIpAddress; 

In ASP.NET 2.1, In StartUp.cs Add This Services:

services.AddHttpContextAccessor(); services.TryAddSingleton<IActionContextAccessor, ActionContextAccessor>(); 

and then do 3 step:

1. Define a variable in your MVC controller

   private IHttpContextAccessor _accessor; 

2. DI into the controller's constructor

   public SomeController(IHttpContextAccessor accessor) {     _accessor = accessor; } 

3. Retrieve the IP Address

   _accessor.HttpContext.Connection.RemoteIpAddress.ToString() 

This is how it is done.