所谓关于ip v9的rfc1606是个愚人节笑话:
http://en.wikipedia.org/wiki/April_Fools%27_Day_RFC
Almost every April Fools' Day (1 April) since 1989, the Internet Engineering Task Force has published one or more humorous RFC documents, following in the path blazed by the June 1973 RFC 527 entitled ARPAWOCKY.
RFC 1606 — A Historical Perspective On The Usage Of IP Version 9. J. Onions. 1 April 1994.