On 3/9/19 18:39, Tom Herbert wrote: > > > On Tue, Sep 3, 2019, 8:31 AM Fernando Gont <[email protected] > <mailto:[email protected]>> wrote: > > On 3/9/19 17:33, Templin (US), Fred L wrote: > > Why was this section taken out: > > > >> 1.1. IP-in-IP Tunnels > >> > >> This document acknowledges that in some cases, packets must > be > >> fragmented within IP-in-IP tunnels > [I-D.ietf-intarea-tunnels]. > >> Therefore, this document makes no additional recommendations > >> regarding IP-in-IP tunnels. > > > > Tunnels always inflate the size of packets to the point that they > may exceed > > the path MTU even if the original packet is no larger than the > path MTU. And, > > for IPv6 the only guarantee is 1280. Therefore, in order to > robustly support > > the minimum IPv6 MTU tunnels MUST employ fragmentation. > > Isn't that an oxymoron? If fragmentation is fragile, if you need > something robust, you need to rely on something else.... > > > Not really, to say fragmentation is fragile is a subjective statement, > not a quantifiable fact.
RFC7872. IIRC, Geoff did his own independent measurements. > As discussed on the list, fragmentation is > productively in use in many networks that employ tunneling. In those > cases fragmentation is not fragile and so there's nothing to fix. The measurements I've seen about fragmentation on the big-I internet seem to indicate that it is fragile. Yes, you can always build your own private network where it is not. -- Fernando Gont SI6 Networks e-mail: [email protected] PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492 _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
