21. For a Teredo pseudo-tunnel to operate properly, outgoing UDP packets must be unfiltered. 22. Teredo tunneling software detects a fatal error and stops if outgoing IPv4 UDP traffic is blocked.23. Teredo is an automatic tunneling technique that uses UDP encapsulation and can allegedly cross multiple NAT nodes.24. ;Teredo server : A well-known host used for initial configuration of a Teredo tunnel. 25. ;Teredo server : A well-known host used for initial configuration of a Teredo tunnel. 26. In practice, network administrators can set up a private Teredo relay for their company or campus. 27. Current versions, of Microsoft operating systems enable IPv6 transitional technologies, including Teredo , by default. 28. IPv6, including 6to4 and Teredo tunneling, are enabled by default in Windows Vista and Windows 7. 29. No treatment of timber to prevent attack by " Teredo navalis " has been completely successful. 30. The Teredo client cannot localize a relay by itself ( since it cannot send IPv6 packets by itself ).