IPAddress.IsLoopback Method
public bool IsLoopback(AddressFamily addressFamily)
Determines whether an IP address is a loopback address.
Parameters
- addressFamily: The AddressFamily of the IP address to check. This parameter is used to specify whether the loopback address is IPv4 or IPv6.
Returns
-
trueif the IP address is a loopback address; otherwise,false.
Remarks
Loopback addresses are used for self-communication. For IPv4, the loopback address is 127.0.0.1. For IPv6, the loopback address is ::1.
This method checks if the current instance of the IPAddress class represents a loopback address for the specified address family.
Examples
Example 1: Checking an IPv4 loopback address
using System;
public class Example
{
public static void Main(string[] args)
{
IPAddress ipv4Loopback = IPAddress.Parse("127.0.0.1");
if (ipv4Loopback.IsLoopback(AddressFamily.InterNetwork))
{
Console.WriteLine("127.0.0.1 is an IPv4 loopback address.");
}
}
}
Example 2: Checking an IPv6 loopback address
using System;
public class Example
{
public static void Main(string[] args)
{
IPAddress ipv6Loopback = IPAddress.Parse("::1");
if (ipv6Loopback.IsLoopback(AddressFamily.InterNetworkV6))
{
Console.WriteLine("::1 is an IPv6 loopback address.");
}
}
}
Example 3: Checking a non-loopback address
using System;
public class Example
{
public static void Main(string[] args)
{
IPAddress publicAddress = IPAddress.Parse("8.8.8.8");
if (!publicAddress.IsLoopback(AddressFamily.InterNetwork))
{
Console.WriteLine("8.8.8.8 is not an IPv4 loopback address.");
}
}
}