addresses:

- blocklist 192.88.88.0/24 6to4 anycast
- invalidate 2002::/16

core/java/src/net/i2p/util/Addresses.java

@@ -34,7 +34,7 @@ public abstract class Addresses {
         return !getAddresses(true, false, false).isEmpty();
     }
 
-    /** @return the first non-local address it finds, or null */
+    /** @return the first non-local address IPv4 address it finds, or null */
     public static String getAnyAddress() {
         SortedSet<String> a = getAddresses();
         if (!a.isEmpty())

installer/resources/blocklist.txt

@@ -46,6 +46,7 @@ Friend of the Chinese Floodfill Flooder:159.226.40.3
 <a href="http://www.team-cymru.org/Services/Bogons/http.html">The Team Cymru Bogon List v6.8 03 FEB 2011</a>:172.16.0.0/12
 <a href="http://www.team-cymru.org/Services/Bogons/http.html">The Team Cymru Bogon List v6.8 03 FEB 2011</a>:192.0.0.0/24
 <a href="http://www.team-cymru.org/Services/Bogons/http.html">The Team Cymru Bogon List v6.8 03 FEB 2011</a>:192.0.2.0/24
+<a href="http://tools.ietf.org/html/rfc3068">6to4 Anycast</a>:192.88.99.0/24
 <a href="http://www.team-cymru.org/Services/Bogons/http.html">The Team Cymru Bogon List v6.8 03 FEB 2011</a>:192.168.0.0/16
 <a href="http://www.team-cymru.org/Services/Bogons/http.html">The Team Cymru Bogon List v6.8 03 FEB 2011</a>:198.18.0.0/15
 <a href="http://www.team-cymru.org/Services/Bogons/http.html">The Team Cymru Bogon List v6.8 03 FEB 2011</a>:198.51.100.0/24

router/java/src/net/i2p/router/transport/TransportUtil.java

@@ -111,6 +111,9 @@ public abstract class TransportUtil {
             return true; // or at least possible to be true
         } else if (addr.length == 16) {
             if (allowIPv6) {
+                // disallow 2002::/16 (6to4 RFC 3056)
+                if (addr[0] == 0x20 && addr[1] == 0x02)
+                    return false;
                 try {
                     InetAddress ia = InetAddress.getByAddress(addr);
                     return