to be clear: i can't make any advice as you are using way too
	strange configuration (trying to make address portable across subnets
	using RIPng, nonstandard netmasks, and more).  i don't understand why
	you cannot following the normal configuration practices.
	so you are going into the bush where noone went into, and got a snake
	bite, i don't have any vaccine for that.

itojun