Bob Hinden wrote: > > Martin Rex wrote: > > > > With a fully backwards compatible transparent addressing scheme, > > a much larger fraction of the nodes would have switched to actively > > use IPv6 many years ago. > > Right, just like they could have deployed dual stack many years ago too. Just two days ago I had an extremeley disappointing experience with IPv6. Windows XP 64-bit (aka Win2003sp2) on a local network with a private DNS universe, IPv4 only network, Windows IPv6 protocol stack installed but IPv6 active only on the two virtual network interfaces of VMware. Somehow the DNS servers configured in the network settings had performed only a partial zone reload and were replying only to some queries, failing some DNS queries with server failure or timeout, and one DNS zone had become completely invisible. I noticed the problem suddenly during work because every new connection took ~16 seconds delay to complete. Wondering what was wrong, I started wireshark. I saw Windows2003 send out 23 DNS lookups for AAAA records for the requested hostname over the course of 16 seconds (some of which returned server failure, some of which failed with no such name), until Windows 2003 finally decided to also try a DNS A query--which got immediately successfully answered and the connection was established. The delay affected each and every connection attempt, even when contacting the same host repeatedly (although there is a DNScache service running...). Disabling IPv6 on all network adapters did not stop this Windows AAAA frenzy, I had to actually uninstall the IPv6 protocol stack (an action which immediately kills *ALL* network connectivity of the machine and requires a reboot to recover...) for this AAAA nonsense to end. During the past few years I had two similar encounters with sudden severe connectivity problems on a Windows XP and a Linux installation, and both times, the problem disappeared when I disabled IPv6. It is also significantly easier to configure the firewall for IPv4-only... -Martin _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf