does gif interface blocks/doesn't support packet fragmentation.

i have gif with mtu 1280 (can't be 1500 as 1500 is tunneling interface
mtu).

works until i try to send packet >1280, no fragmentation is performed i
think - no reply.

any fix for this? i can't expect whole IPv6 network will have MTU=1280.

trying to ftp file from machine with IPv6 MTU = 1500 to this machine
(MTU=1280) just doesn't work