Dear Sir Per RFC 3701, "6bone (IPv6 Testing Address Allocation) Phaseout", 3FFE prefixes only remain valid until June 6, 2006. NECTEC-TH would like to return the 3FFE:4016::/32 prefix to the 6bone. Thank you very much for give we use IPv6 from 6bone to develop IPv6 over the past few years. Regards, NECTEC IPv6.