Hi Randy and Brian, I am sure the discussion of the discussion has been had before, but: > > IPv4 provides no mechanism whatever for addresses greater than 32 bits. > > Therefore, mathematically, there is no possible design for an IP with > > bigger addresses that is transparently backwards compatible. We've > > known that since at least 1992. > > i guess you forget the discussion of variable length. i hope we don't have to > rehash it here. > > decisions were made. some were quite bad. v6 had some real zingers. > remember tla/nla? no feature parity, such as dhcp (a war which has not > finished)? it is almost as if it was designed to fail. > > randy I think that the compatibility issue is a key reason why adoption has been difficult. Others are: No compelling IPv6 only features -> From my reading several key features were directed at IPv6 only originally, like IPsec. Successive works to provided all non-address IPv6 features in IPv4. -> This in part is being addressed by helpful capabilities such as DHCPv6PD (although we could kill things entirely by back porting this to IPv4 ;-) No local use benefit -> Ostensibly deploying IPv6 only gets you (slightly) more work. -> compare this to transformative technologies such as Ethernet and IPv4, which had a better price point and enabled new local capabilities, which did not rely on neighbours adopting the same protocol. Of course, these are short-sighted analysis. Being able to uniquely address a peer device is a key benefit which we will see drive adoption once 103.X/8 is gone. Another key benefit is local addressability which handles organizational merges/changes/private peering with ULAs (resolves the RFC-1918 collision problem). For a few years I have been involved in an extremely pragmatic market where people want to see the money they will save by deploying a networking technology. What would get my customers adopting would be a compelling TCO argument. Sincerely, Greg Daley Solutions Architect Logicalis Australia Pty Ltd gdaley@xxxxxxxxxxxxxxxx t +61 3 8532 4042 m +61 401 772 770 _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf