That would be quite a different algorithm than RFC3041. If you want something like what you mean though, you could script it and then crontab it. Effectively what you need to do is mark old addresses as 'deprecated' so that they don't get used for new connections, add a new random one and and then delete them when there are no connections left using those addresses. I personally really do not see the advantage of RFC3041, the only bit that there is an arg for is that it is not your MAC address anymore, but you can then just also override that portion of the EUI-64 address and presto. You also have to realize that the privacy is limited as people who want to track will just correlate you first as a single /64, then as a /48.