Comments below. > On Sep 5, 2019, at 11:33 PM, Ole Troan <[email protected]> wrote: > > Bob, et al, > > I have two issues with this text. > > 1) It introduces something new and undescribed in paragraph 2. > "unless they also include mechanisms to detect that IP fragmentation isn't > working > reliably." > That seems like hand-waving to me. Suggest deleting.
Fragmentation success or failure is directly testable. Any feedback mechanism will work and specific ones are mentioned elsewhere (PLPMTUD). This differs from ICMP black-holing in path MTU detection. > > 2) Paragraph 4: > "The risks of IP fragmentation can also be mitigated > through the use of encapsulation, e.g., by transmitting IP fragments > as payloads." > > This seems like proposing new unspecified solutions with it's own set > of considerations. Specific widely-deployed methods are mentioned elsewhere in the doc, including GRE and UDP. > IP fragmentation is a general solution to all hosts, > encapsulation is certainly not in every host, Actually, it is - unless you’re claiming hosts don’t support UDP. > and has different > properties with regards to NAT traversal etc. If by “different” you mean “much more likely to succeed”, agreed. > vAlso if encapsulation > was the answer, other segmentation / reassembly that were tunnel > specific could be developed. It is and is widely used - IPsec tunnels over UDP, e.g. > Regardless this also amounts of hand-waving > and doesn't seem to offer any advice that can be heeded now. > And of course encapsulation can also exacerbate the problem > by increasing packet size. Yes, it makes the fragments smaller, which may be additional effort/performance impact, but it completely hides its impact on successful forwarding. --- _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
