source of a socket error message

[Mark Wieder]

On 7/18/19 8:11 AM, dsc--- via use-livecode wrote:
> Also...
> 
> If you have control of these sites and even if you use an ISP DNS service, you can add a secondary DNS IP address, perhaps a public recursive name server such as the Google Public DNS (8.8.8.8).  This will add a robustness without upgrading the software.
> 
> If you don't manage those, you can you can upgrade the software to access a public name server directly with TLS, or use DNS over HTTPS. DNS over HTTPS is not as easy as it sounds, but should be doable. It is available without filtering from Google, Quad9 (use 9.9.9.10 for no filtering), or (if you don't use Cisco) Cloudflare 1.1.1.1.

DoH is getting easier to use all the time but still hasn't reached a 
level of plug-and-play availability. I set up a Raspberry pi on our LAN 
running a DoH service that hooks into Cloudflare on the backend and it's 
transparent and painless (if I'm allowed to mix metaphors).

Normally I'd agree with you on this, but what has me worried about the 
problem situation is "occasionally I get a "mass" of errors (50 or 60) 
within a 1 hour period of time from a large variety of different 
external sites". So it's not a DNS outage from a single location,

That said, last week I had a maddeningly similar thing occur here... I 
suddenly couldn't resolve addresses, and worse, couldn't even ping 
numeric addresses outside our ISP's gateway. After working with our 
ISP's tech support, rebooting our router got us a new IP address in the 
router's routing table and that fixed the problem. Possibly some problem 
with fiber DHCP refreshing, and I hesitate to suggest that something 
similar is at work here, but strange things happen.

> 
> You might want to add some network diagnostics, where you can log or otherwise report the results. This will help solidify your analysis.
> 
> If you have control over the server and know the IP address will never change, you can skip the name lookup and just use the IP address.

That or your excellent suggestion of cacheing the address once it's 
originally resolved.

-- 
  Mark Wieder
  ahsoftware at gmail.com