> On 2021-07-21, at 21:36, Michael Richardson <mcr+i...@sandelman.ca> wrote: > > Signed PGP part > > Esko Dijk <esko.d...@iotconsultancy.nl> wrote: >> There is already a "CoAP ping" described in RFC 7252 that can be >> used. It does not access any resource, just the CoAP server endpoint at >> CoAP message layer. As a side effect of this ping your DTLS stack will >> set up the connection which is handy. > > I recalled that later in the day that CoAP "ping" is not connected to CoAP > "echo" :-)
The Echo option is not an echo in the sense of an ICMP echo. (Maybe we should fix the name to “cookie”.) > I think that there is also potentially a need for a way to debug possible MTU > issues. Good point, CoAP Ping (empty CON messages) cannot do that. Actually, the fact that it was possible to set up DTLS should give one considerable confidence; the CoAP Ping is not needed to verify pure presence. Verifying that that server actually speaks a specific protocol would need to be part of that protocol though. Also, cough, cough, https://datatracker.ietf.org/doc/html/rfc6520 gives you a nice way to ping a DTLS server with different MTU sizes. (Ignoring the fact that an incorrect implementation led to the biggest TLS, er, “event” we ever had.) Grüße, Carsten _______________________________________________ Anima mailing list Anima@ietf.org https://www.ietf.org/mailman/listinfo/anima
