I have a pool of a /56 network.
I want to assign ipv6 addresses from my lan interfaces using only "::1/64" command.
But how do I make sure that ether5 always gets the first prefix from the pool, ether6 the second and so on?

I remember there was something like add address=::1:0:0:0:1/64 from-pool=TT, but then I get error address pool error: bad preferred prefix!

I have seen cases where the interface will get another order from the pool, and thus mismatching client prefix when router reboots.

Unfortunately you cannot, it is an annoying omission from RouterOS.

Unfortunately you cannot, it is an annoying omission from RouterOS.

I am pretty sure I have seen a workaround on this before ?

Anyways, if I am remembering wrong, how do you make sure clients removes the ipv6 address in the wrong prefix if this happens after reboot?
Can mikrotik send old RA with a short router lifetime timeout to make sure clients withdraw this address, and only uses new prefix?

Some time ago I made this script. I can't say that I like it very much, but it should be usable until there's some better solution.