answer on the question of why it would need on-the-fly fragmenting: 1.)
it's life easier when tracking layer-3/4 headers and messing with packet
NAT, but that's not important anymore)
You confirmed yourself that it is meaningless purpose.
Sorry. Well, enough on NAT.
and 2.) in case the idiot on the
end won't allow an MTU of 1500 ;-)
This just sounds as full non-sense to me. What is special with 1500?
I read somewhere that the correct size for an IPv6 link was 1500.
Is this wrong? Is the correct MTU smaller? If it is, then sorry in