Steven Bellovin wrote:
NAT didn't really exist when the basic shape of v6 was selected.
Yes, it did. At 27th IETF in 1993, there was a NAT BOF: http://www.ietf.org/proceedings/27.pdf The following BOFs and working groups in the Internet Area met during the Amsterdam IETF: ¯ Network Address Translators BOF (NAT) If I remember correctly, there was an informal BoF at 26th. RFC1631 was published in 1994. Granted that there were not much operational experiences on NAT accumulated, when RFC1883 was published in 1995. However, it is not an excuse for IETF poorly designed IPv6, because IPv6 must and could have designed to avoid operational problems before operational experiences on IPv6 was accumulated. Masataka Ohta