On Tue, Aug 5, 2025 at 7:52 AM Jen Linkova <furry13@xxxxxxxxx> wrote:
Hi Bill,
On Tue, Aug 5, 2025 at 8:19 AM Bill Fenner <fenner@xxxxxxxxxx> wrote:
>> A question: if [I-D.ietf-intarea-rfc8335bis] acknowledges that inferring the
>> length is suboptimal, and this draft solves the issue: what prevents us from
>> using the mechanism defined in THIS document for [I-D.ietf-intarea-rfc8335bis]?
>> Is it just because this draft was written before I-D.ietf-intarea-rfc8335bis?
>> Now this draft seems to "overtake" [I-D.ietf-intarea-rfc8335bis], so I'm
>> wondering: if it gest published before [I-D.ietf-intarea-rfc8335bis] - would it
>> make sense for [I-D.ietf-intarea-rfc8335bis] to use it?
>
>
> When I started the rfc8335bis update, I started with an implementation survey. None of the implementations that I could find actually implemented what RFC8335 + RFC4884 specify : in particular, they all added extra data after the extension objects, where RFC4884 implies that the extension objects extend to the end of the packet.
>
> We decided that my update would reflect with the deployed implementations, as opposed to trying to say that they're incorrect (by strictly requiring RFC4884 behavior) or incomplete (by defining an RFC4884 object for "extra data after the ping").
>
> Defining RFC8335bis to use icmp-exten-hdr-len is contrary to that decision. If we have carte blanche to redefine the PROBE packet format, I'd rather just have defined an RFC4884 object for extra data and use that.
Ah yes, thanks for refreshing my memory on this, I did forget the
details of that story.
It all makes sense but there is no reason for future implementations
of the PROBE to also use the length field, right?
(Let's say I'm writing a new library to support ICMP extensions, after
draft-ietf-intarea-icmp-exten-hdr-len is published. Now, when crafting
the ICMP extension header for a packet, I'd either need to handle
PROBE packets differently from any other packets (set length = 0) or
just set the length).
Anyway this discussion is more in scope for rfc8335bis than for
draft-ietf-intarea-icmp-exten-hdr-len.
Ok.
RFC8335bis just says "use RFC4884" and says almost nothing about the 4884 packet format, so as long as draft-ietf-intarea-icmp-exten-hdr-len updates RFC4884, I don't know that there's anything to say in 8335bis.
Bill
-- last-call mailing list -- last-call@xxxxxxxx To unsubscribe send an email to last-call-leave@xxxxxxxx
