> -----Original Message----- > From: ipv6-boun...@ietf.org [mailto:ipv6-boun...@ietf.org] On Behalf Of > Teemu Kiviniemi > Sent: Sunday, March 27, 2011 9:53 PM > To: teemu.savolai...@nokia.com > Cc: beh...@ietf.org; ipv6@ietf.org > Subject: Re: RFC3484-revise and NAT64 Well-Known Prefix > > On Sun, 27 Mar 2011, teemu.savolai...@nokia.com wrote: > > > I discussed shortly with Arifumi about RFC3484 default policy table > > updates and NAT64 WKP, i.e. whether the default policy table should > take > > a stand on 64:ff9b::/96 preference. > > > > It seemed to us that default policy table does not necessarily have > to, > > as it could be ok to handle addresses with WKP similarly to global > IPv6 > > addresses. Furthermore, the default policy table anyway cannot cover > > Network-Specific Prefixes. > > > > Hence prefixes used for protocol translation would be handled like > > global IPv6 addresses unless something different is configured via > > policy distribution mechanism? And this should perhaps be documented > > into the RFC3484-revised. > > I believe native IPv4 should always be preferred over NAT64. Even if > native IPv4 was using NAT, it is likely to work better with current > applications than NAT64. > > Preferring IPv4 over the NAT64 well-known prefix does not fix the > problem > for network-specific NAT64 prefixes. However, I see no reasons why the > NAT64 WKP should not be given a lower preference than IPv4 by default.
One reason is that it changes behavior for a network using the well-known NAT64 prefix versus using their own network's NAT64 prefix. Not to mention they won't know if/when their IPv6 devices are using the new RFC3484 default table, and will thus start shifting their preference away from IPv6 (and a NAT64) and towards IPv4 (and a NAPT44, because let's be real, everyone will have a NAPT44 if we're talking about an RFC3484 change). Personally, I don't see any benefit to changing RFC3484 table to accomodate NAT64, assuming there is a way for the host to learn its NAT64 prefix (draft-korhonen-behave-nat64-learn-analysis). Assuming there is no standard way to learn the prefix by the time we would want to standardize rfc3484bis, I see harm in adding the NAT64 well known prefix 64:ff9b::/96 to the default policy table. -d > -- > Teemu > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
