review ttl on dns A / AAAA records for some servers

Some servers' DNS TTLs are very very short and the ipv4 ttls don't match the ipv6 ones. If this is a rotation load-balancing scheme then my apologies. But if not I think the numbers should all be reviewed just in case, and if at all possible ttls could be put up to something really high. Usual reasons - to give users better performance and reduce the load on the dns, even though that might be a pain for admins one day because of the need to prepare well ahead should changes be required.