On 7/9/22 09:02, poindexter FORTRAN wrote:
>> Keep in mind an SRV record hostname must point to a servers A or
>> AAAA address and not a CNAME. Otherwise, seems reasonable.
>
> My experience setting up DNS is long in the past, Bind 4.9 in 1993?
>
> I don't recall if there was any downside to setting multiple A records
> pointing to one IP, versus one A record with multiple CNAME records
> pointing to it?
>
> No downside, aside from having to change multiple DNS entries when the
> originating IP changes?
You can pretty safely have longer lifetimes for CNAME than you'd want to
use for A records. I generally set CNAME for at least a week, and A
records for 15m to a day.
Depending on the DNS server, the round-trip for two requests could
impact things. If you care about the time to render a website, it can
matter a lot. Don't know if it's changed, but GoDaddy's DNS servers had
particularly bad latency for most people, and handled a high portion of
the internet. Which is a large part of why google created their
distributed DNS that sometimes exceeds the specified timing in favor of
cached results. Going under 15m for A record likely will be ignored by
Google's DNS cache.
It's not too hard to do your own caching DNS lookups. I use pihole
locally and fall back to the Cloudflare DNS servers, I have less trust
of Google over time even though a lot of my domains have DNS at Google,
I like their registrar interface, but considering moving them all.
--
Michael J. Ryan - tracker1@roughneckbbs.com
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