Hi, Ole,
On 2/14/2017 10:33 AM, otroan(_at_)employees(_dot_)org wrote:
*If* you care about packet loss, then your only option is to probe the path
with with
synthetic data that exactly mimics the live data, or not to probe at all and
live
with the 1280. As I said 1280 is pretty close to 1496 which is all most
networks
will give you in practice.
Yes, but sending at 1280 does not work for IP tunnels. The whole purpose of
the minimum MTU was to give space for tunnel headers (1500-1280).
I'm in the process of revising draft-intarea-tunnels to make this more
clear, as well as to provide a TSV ART review of this doc, but in preface:
There are two IPv6 minimum sizes: link MTU of 1280 and EMTU_R of 1500.
Support for source fragmentation and the difference between these two
values is what gives space for tunnel headers.
No amount of link MTU management can ever avoid source fragmentation
without violating the link MTU minimums in RFC2460.
Joe