DNS Lookup Nonsense

Question

I recently transferred my domain to a new registrar, and after the transfer was complete, updated my nameservers to point to completely different ones.

This was about 12 hours ago. Since then, I've had all kinds of strange issues trying to access my website, most of which I assume have to do with DNS propogation delays because of DNS caching. I understand that you usually have to wait for 24 hours to be sure that the DNS records change has fully propogated, BUT I'm not sure why this is happening:

1) Using Ubuntu on my laptop connected to my home Wifi, I cannot access my website. Chrome shows DNS lookup failure: error: -105 (ERR_NAME_NOT_RESOLVED)

2) Using my phone's Wifi, I cannot access my website (DNS lookup fails, chrome gives same result on my phone). However, using my 4G data I can view the website perfectly fine.

Now those two make sense to me: Maybe my ISP is caching the DNS lookup (although I'm not sure why it would do this if the lookup is failing).

3) My laptop fails when doing a ping of my website. HOWEVER, dig works fine - sometimes! If I run dig www.mywebsite.com it fails, but if I do dig http://www.mywebsite.com it works! (something similar happens with nslookup: it only works with a http://)

Can anyone explain what is going on here?

Answer 1

I got the same issue (works via VPNs, mobile and other wifi, just not my wifi), and I think it is as @milli mentioned, to do with the TTL (Time-to-live) caching of DNS records.

My DNS host has a feature to lower the TTL record to 5 minutes when changing servers, etc. Perhaps you can find and enable that feature or contact your DNS host for information if they support that.

This website has further info: https://www.dnswatch.info/articles/dns-update

Answer 2

Yes, tt can take up to 24 hours for the change at a registrar, although most are fast (takes minutes at most registrars through their web sites). If your old DNS hosting place used the standard 2-day TTL (time-to-live) or is no longer authoritative, it can take up to an additional 48 hours after the change for the NS records to flush from caches everywhere, particularly in the case where the old place is not answering authoritatively... the default TTL for NS records at the com, net and org (and most other) top-levels is 2 days and comes into play in the latter case..

And you maybe checked your website before you made the change, right? That means your ISP just cached the old NS record set and will probably take the longest to switch over.

Anyway, works fine for me:

$ dig www.mywebsite.com

; <<>> DiG 9.9.3 <<>> www.mywebsite.com
;; global options: +cmd
;; Got answer: ;; ->>HEADER<<- opcode: QUERY,status: NOERROR, id: 11939
;; flags: qr rd aa ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;www.mywebsite.com.             IN      A

;; ANSWER SECTION:
www.mywebsite.com.      10800   IN      A     216.250.121.107

(Yes, can't really verify any of this if you don't put in real DNS names...)

Also, dig is a DNS troubleshooting tool. It only understands domain names, not URIs. And it doesn't behave the same as the DNS resolver code in the system that the web browser uses.