Re: [DNSOP] New Version Notification for draft-pusateri-dnsop-update-timeout-00.txt

[Mark Andrews <[e-mail]>]

Active directory has each domain controller updating its own SRV record
on the same <qname,qtype,qclass> tuple.  These updates happen at different
times and need to expire if a domain controller becomes unreachable.

A different case is when you have multiple prefixes from different
providers with different lifetimes.  You then end up with multiple AAAA
records that need to expire at different times.

Mark

> On 28 Aug 2018, at 8:34 am, Ted Lemon <[e-mail]> wrote:
> 
> Sorry, I realized that I accidentally hit "reply" instead of "reply all."
> 
> The issue that I raised with Tom is that for the DNSSD SRP use case, the only names that receive updates from multiple services are service names (IOW, not service instance names).   In the case of SRP, PTR RRs in service names always point to service instance names, which are per-service, and hence can be counted on to expire on a single schedule.   So for the use case of SRP, the easiest way to handle deleting service name PTR RRs is to take advantage of the semantics of DNSSD: when a service instance SRV record expires, also delete the PTR RR on the service name that points to it.
> 
> The reason I bring this up is that it's the most complicated use case I know of.   Is there some other use case where we expect more than one DNS Update client to be updating RRs of the same type on the same name?   How would this even work without SRP semantics?   If this is not expected, then any complexity in the timeout RR that's present only to support that use case is unnecessary.
> 
> This is what has been motivating my questions about use cases.   I'm sorry I didn't make that clear earlier.

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
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