/// <summary>
/// Gets an IP address by name, via DNS.
/// </summary>
/// <param name="hostname">The hostname.</param>
/// <returns>The corresponding IP address.</returns>
/// <remarks>
/// <para>Returns the first IP v4 address available, if any,
/// else the first IP v6 address available. Throws if it cannot
/// get an IP for the hostname via DNS.</para>
/// </remarks>
// ReSharper disable once InconsistentNaming
public static IPAddress GetIPAddressByName(string hostname)
{
if (hostname == "0.0.0.0")
{
return(IPAddress.Any);
}
var addresses = HDns.GetHostAddresses(hostname);
// prefer an IP v4, if possible
return(addresses.FirstOrDefault(x => x.AddressFamily == AddressFamily.InterNetwork) ??
addresses.FirstOrDefault());
}
/// <summary>
/// (internal for tests only)
/// Gets all scoped IP addresses corresponding to a non-scoped IP v6 local address.
/// </summary>
/// <returns>All scoped IP addresses corresponding to the specified address.</returns>
internal static IEnumerable <IPAddress> GetV6LocalAddresses()
{
// if the address is IP v6 local without a scope,
// resolve -> the local address, with all avail scopes?
var hostname = HDns.GetHostName();
var entry = HDns.GetHostEntry(hostname);
foreach (var address in entry.AddressList)
{
if (address.AddressFamily == AddressFamily.InterNetworkV6)
{
yield return(address);
}
}
}