c#中要判断输入的IP格式是否正确，该怎么写正则表达式啊，函数该怎么写
c#中要判断输入的IP格式是否正确，该怎么写正则表达式啊，函数该怎么写啊，求解？

------解决方案--------------------
/// <summary>
/// 是否为ip
/// </summary>
/// <param name="ip"></param>
/// <returns></returns>
public static bool IsIP(string ip)
{
return Regex.IsMatch(ip, @"^((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)$");
}

public static bool IsIPSect(string ip)
{
return Regex.IsMatch(ip, @"^((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){2}((2[0-4]\d|25[0-5]|[01]?\d\d?|\*)\.)(2[0-4]\d|25[0-5]|[01]?\d\d?|\*)$");
}