Here you can find the source of isIPv6UniqueSiteLocal(InetAddress address)
private static boolean isIPv6UniqueSiteLocal(InetAddress address)
//package com.java2s; //License from project: Open Source License import java.net.InetAddress; public class Main { private static boolean isIPv6UniqueSiteLocal(InetAddress address) { // ref: https://en.wikipedia.org/wiki/Unique_local_address // currently undefined but could be used in the near future fc00::/8 return (address.getAddress()[0] & 0xFF) == 0xFC // in use for unique site-local fd00::/8 || (address.getAddress()[0] & 0xFF) == 0xFD; }// www .j a v a 2 s.c o m }