试试这个。

var host = Dns.GetHostEntry(Dns.GetHostName());
        foreach (var ip in host.AddressList)
        {
            if (ip.AddressFamily == AddressFamily.InterNetwork)
            {
                 ipAddress = ip.ToString();
            }
        }

可以添加一些回退逻辑来处理负载均衡器的存在。

此外，通过检查，即使没有负载均衡器，X-Forwarded-For报头也会被设置(可能是因为额外的Kestrel层?):

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);
}

假设_httpContextAccessor通过DI提供。

在IIS上使用负载均衡器运行。net core(3.1.4)不能与其他建议的解决方案一起工作。

手动读取X-Forwarded-For报头可以。 这段代码假设这个报头包含一个IP。

IPAddress ip;
var headers = Request.Headers.ToList();
if (headers.Exists((kvp) => kvp.Key == "X-Forwarded-For"))
{
    // when running behind a load balancer you can expect this header
    var header = headers.First((kvp) => kvp.Key == "X-Forwarded-For").Value.ToString();
    // in case the IP contains a port, remove ':' and everything after
    ip = IPAddress.Parse(header.Remove(header.IndexOf(':')));
}
else
{
    // this will always have a value (running locally in development won't have the header)
    ip = Request.HttpContext.Connection.RemoteIpAddress;
}

感谢@JawadAlShaikh和@BozoJoe指出IP可以包含一个端口，x - forward - for可以包含多个IP。

您可以使用IHttpConnectionFeature来获取此信息。

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

在ASP。NET 2.1，在StartUp.cs中添加此服务:

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

然后做3步:

在MVC控制器中定义一个变量 private IHttpContextAccessor _accessor DI转换为控制器的构造函数 IHttpContextAccessor访问器 ｛ _accessor = accessor; ｝ 检索IP地址 _accessor.HttpContext.Connection.RemoteIpAddress.ToString ()

事情是这样的。

运行ASP。在Ubuntu上的Traefik反向代理后面的NET Core 2.1，我需要在安装官方的Microsoft.AspNetCore.HttpOverrides包后在knownproxy中设置它的网关IP

        var forwardedOptions = new ForwardedHeadersOptions {
            ForwardedHeaders = ForwardedHeaders.XForwardedFor,
        };
        forwardedOptions.KnownProxies.Add(IPAddress.Parse("192.168.3.1"));
        app.UseForwardedHeaders(forwardedOptions);

根据文档，如果反向代理没有在本地主机上运行，这是必需的。docker-compose。Traefik . yml已分配静态IP地址:

networks:
  my-docker-network:
    ipv4_address: 192.168.3.2

或者，它应该足以确保在这里定义了一个已知的网络，并在. net Core中指定其网关。