Domain not found periodically

General
1

Cloudflare DNS name servers are not consistently resolving my websites. Several sites are affected, but I will use worldwidedirectory.apsnet.org as the example.

We use StatusCake to monitor websites and StatusCake uses Cloudflare DNS servers.

We use Network Solutions and network solutions name servers.

For example, at 2023-02-03 18:51:16 GMT Cloudflare name servers quit resolving this domain. 31 minutes later they resumed resolving this domain (see attached). During this entire time Network Solutions DNS servers successfully resolved this domain.

I’m hoping someone can shed some light on why Cloudflare DNS servers go from resolving to not resolving and back to resolving. No changes are being made at Network Solutions and other DNS servers are not exhibiting this behavior.

Any insight is greatly appreciated.

2

In my own experience, DNS Resolvers are really good at caching answers and retrying, even when your actual nameservers are very flakey and not answering correctly.

The root of your issue seems to be your nameservers, ns63.worldnic.com. and ns64.worldnic.com.

They seem very “flakey” and only resolve sometimes, servfail others.

dig a apsnet.org @ns63.worldnic.com

; <<>> DiG 9.16.33-Debian <<>> a apsnet.org @ns63.worldnic.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 52282

Using the various recursive resolvers

dig a apsnet.org @1.1.1.1

; <<>> DiG 9.16.33-Debian <<>> a apsnet.org @1.1.1.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11572
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

dig a apsnet.org @8.8.8.8

; <<>> DiG 9.16.33-Debian <<>> a apsnet.org @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 215

dig a apsnet.org @9.9.9.9

; <<>> DiG 9.16.33-Debian <<>> a apsnet.org @9.9.9.9
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16466

1.1.1.1 and 9.9.9.9 work, 8.8.8.8 doesn’t, but it did work properly later.

So it looks like your status monitoring using Cloudflare was just a red herring, guessing you don’t use any other monitoring platforms that use different recursive resolvers to see the issue.

Edit: Using a third party tool here, DNS Check | Ping.Sx, make sure you specify the node resolver as the IP of your nameserver, ns63.worldnic.com, 162.159.26.185
You can see that most of them are servfail. Although it does seem a bit better now?

1 Like
3

Thanks for the response. This is helpful. It is better now, but it seems random when it quits working. I will pursue the issue with Network Solutions.