Get IP Address in ASP.NET Core 3.x

This page summarize information about how to retrieve client and server IP address in ASP.NET core applications. 

Get client user IP address

Client IP address can be retrieved via HttpContext.Connection object. This properties exist in both Razor page model and ASP.NET MVC controller. Property RemoteIpAddress is the client IP address. The returned object (System.Net.IpAddress) can be used to check whether it is IPV4 or IPV6 address. 

public string ClientIPAddr { get; private set; }

public async Task<IActionResult> OnGetAsync()
{
	// Retrieve client IP address through HttpContext.Connection
	ClientIPAddr = HttpContext.Connection.RemoteIpAddress?.ToString();
	return Page();
}

Get server IP address

Server or local IP addresses can be retrieved through HttpContext connection feature (IHttpConnectionFeature).

public string LocalIPAddr { get; private set; }

public async Task<IActionResult> OnGetAsync()
{
	// Retreive server/local IP address
	var feature = HttpContext.Features.Get<IHttpConnectionFeature>();
	LocalIPAddr = feature?.LocalIpAddress?.ToString();

	return Page();
}

Alternatively, server address can be retrieved through DNS.

For example, the following code runs in Razor page views directly:

@{
	var hostName = System.Net.Dns.GetHostName();
	@hostName
	<br />
	var ips = await System.Net.Dns.GetHostAddressesAsync(hostName);
	foreach (var _ in ips)
	{
		@_
		<br />
	}
}

The output looks like the following when run the code in a local development machine:

***
172.28.0.1
192.168.119.1
192.168.64.1
192.168.1.103
::1

Multiple IP addresses are shown for all the available networks. 

The above example can also work in Console or Desktop application which doesn't have a HttpContext in the process.