Hi Mikael, Thanks for your careful review. Responses inline.
Ron > -----Original Message----- > From: Mikael Abrahamsson <swm...@swm.pp.se> > Sent: Tuesday, March 6, 2018 4:57 AM > To: Ron Bonica <rbon...@juniper.net> > Cc: int-area@ietf.org > Subject: Re: [Int-area] draft-bonica-intarea-frag-fragile-01 > > On Mon, 5 Mar 2018, Ron Bonica wrote: > > > Folks, > > > > Please review draft-bonica-intarea-frag-fragile-01 and provide comments. > > The URL is > > https://urldefense.proofpoint.com/v2/url?u=https- > 3A__tools.ietf.org_html_draft-2Dbonica-2Dintarea-2Dfrag-2Dfragile- > 2D01&d=DwIBAg&c=HAkYuh63rsuhr6Scbfh0UjBXeMK- > ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl- > AWF2EfpHcAwrDThKP8&m=rEnXuPqkshyKZKBjvbX5C4azFkl4x3umDYP- > M8MPk9k&s=fzVLPQb705xxBUc4zque37mctCX2lPbU4hREEMOtsjU&e=. > > I like it. > > 4.6. There are cases where this "misconfiguration" is due to vendor default > not being changed. I do not equate "misconfiguration" with "didn't change > default configuration". Some others might. It might also be due to "hardware > limitation". Generally, I do not like the "filtering" (I have opposed to this > in > other drafts), as for me "filtering" conveys intent. If there is no intent, > there > is no filtering, but instead there is "dropping" > or some other word. Agree. I have expanded this text in the next draft version. > > 4.7 Can we please have 4.7 that describes cases where ICMP PTB are never > emitted because of misconfiguration? For instance intermediate L2 switch > that has lower MTU than the L3 nodes connected to it, or mismatched > MTU/MRU on two nodes connected to each other. I have added this text in Section 7.2 saying that network devices must be configured so that they emit ICMP PTBs when required to do so. > > 5.1. Can we have some kind of strong recommendation that hosts enable > PLMTUD for TCP? > While I agree with this recommendation, I am not sure if the INT AREA is empowered to make it. Wouldn't such a recommendation have to come from the TSV area? > 6. "IP encapsulations". Shouldn't this be "some packet-in-packet > encapsulations"? Or does "IP encapsulations" mean "anything encapsulated > in IP"? 6.3 talks about this as well, I think it's worthwile to put in a > sentence > that whatever is said in this document, probably applies to all kinds of > encapsulations. I have changed the term "IP encapsulations" to "Packet-in-packet encapsulations" > > 6.1. Err, last paragraph, aren't we getting ahead of ourselves here? I guess > this is because of Geoff Hustons claims? That last paragraph is in dispute > (I'd > say, from talking to other people involved in DNS). > I will defer to Geoff on this one. > 7.2. I strongly believe we need more text here. It should be something along > the lines of: > > "As per RFC4890, network operators MUST assure proper operation of > PMTUD by making sure that PTB packets are emitted by all equipment when > it can't fit a packet into a smaller MTU link, and that large MTU packets are > not silently discarded due to misconfiguration. Network operators MUST > NOT filter ICMP PTB packets." Agree. It is in the next version > > ... > > As a last comment, do we know documents that tell application developers > how to do what this document recommends in 5.2? If someone developers > applications that use UDP for instance, how do they know what the > operating system PMTUD is at any given time, to avoid the host stack > fragmenting the packet? I've been interacting with people who had this > specific problem, and it wasn't easy to figure out exactly how to do what > is being said in this text (which I agree should be done). > If I understand you correctly, such documentation would be available on per-OS basis. > Generally, I think the IETF should strongly recommend application/protocol > developers to not rely on IP fragmentation, generally. So the ones listed > in 6 (and I imagine there are more of them), should change the way the > protocol is done. This includes DNS. So all working groups should be put > on notice to start working on this problem if they don't already have a > solution for it. > This draft is intended to bring the IETF community to the conclusion that you have drawn. Ron > -- > Mikael Abrahamsson email: swm...@swm.pp.se _______________________________________________ Int-area mailing list Int-area@ietf.org https://www.ietf.org/mailman/listinfo/int-area