IPv6 and IPv4 can be expected to coexist for a long time. Individual ISPs can start supporting IPv6 whenever they believe that it is in their interests to do so; some are doing so already. IPv4 and IPv6 can be run over the same media, at the same time. So IPv6 does not, in general, require a new modem. In some cases where the ISP supplies a box to the customer that does more than just transmit IP packets to and from the customer's network (for example, boxes that act as DHCP servers), an upgrade to that box will be advantageous. However there are standard ways of transmitting IPv6 packets over IPv4 so even legacy routing equipment can be used to connect to IPv6. Most computers and web browsers these days can support IPv4 and IPv6 at the same time. If a web site supports IPv6, the site's IPv6 address will be used, but if the site still supports only IPv4, the IPv4 address will be used. This is a bit simplified but it is basically how things work. In addition to web browsers, most other applications in use today can tolerate a mixture of IPv4 and IPv6 nodes. > There's a lot of discussion on these lists about switching to IPv6 and > what technical changes/implementations will be necessary for ISP's > when the move is made but when will the move be made? Will the move be > gradual so that users who have a IPv4 modem will have time to exchange > the modem for a IPv6 compatible one? What will happen to websites on > networks that haven't yet moved over to IPv6? _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf