private IHttpContextAccessor _accessor;

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

_accessor.HttpContext.Connection.RemoteIpAddress.ToString()

public void ConfigureServices(IServiceCollection services)
{
     services.AddMvc();
     services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}

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