Re: v6 DNSSEC fail, was Buying IPv4 blocks

[Brandon Martin <lists.nanog () monmotha net>]

On 10/7/18 11:47 PM, Naslund, Steve wrote:
> That is true provided that you accept that some people may not be able to respond without the packet getting fragmented 
> due to tunneling or a million other reasons they may not support that MTU.   Nonstandard MTU has always and seems will 
> continue to be problematic.  It all really began with tunneling which by its nature lowers the MTU available to the 
> application.  Firewalls really have to just deal with it and do the re-assembly they need to.  It does create 
> tremendous performance issues for these devices at high bandwidth.  Bottom line is fragmentation sucks and V6 does not 
> make it any better.

Except that, in IPv6-land, anyone with effective MTU < 1280 has the onus 
put on them to "make things work" i.e. come up with an adaptation layer 
or some sort of tunnel-layer transparent fragmentation.  If you're 
relying on The Internet to fragment to <1280 for you, you're bound to 
see breakage.  I'd like to think we can safely ignore this case in terms 
of operations.
--
Brandon Martin