[dns-operations] bit.ly serial number (and content) desynchronisation

[Chris]

On 2026-02-13 02:33, Stephane Bortzmeyer via dns-operations wrote:
> While all the authoritative name servers for bit.ly currently have the
> same serial number (1), my resolver got a SOA with a different number,
> and a different content (no A and no AAAA):
> 
> % dig bit.ly
> 
> ; <<>> DiG 9.18.39-0ubuntu0.24.04.2-Ubuntu <<>> bit.ly
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64698
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
> 
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags: do; udp: 1232
> ;; QUESTION SECTION:
> ;bit.ly.            IN A
> 
> ;; AUTHORITY SECTION:
> bit.ly.            6623 IN    SOA ns-1372.awsdns-43.org. 
> ns-cloud-c3.googledomains.com. (
>                 2003080406 ; serial
>                 10800      ; refresh (3 hours)
>                 3600       ; retry (1 hour)
>                 604800     ; expire (1 week)
>                 21600      ; minimum (6 hours)
>                 )
> 
> ;; Query time: 4 msec
> ;; SERVER: 192.168.2.254#53(192.168.2.254) (UDP)
> ;; WHEN: Fri Feb 13 11:24:42 CET 2026
> ;; MSG SIZE  rcvd: 121
> 
> Testing with RIPE Atlas probes
> <https://atlas.ripe.net/measurements/154580059>, I see that I'm not
> the only one who got this serial number 2003080406.
> 
> Temporary error in publication? Or an anycast instance somewhere
> serving a wrong zone?

Frankly. There's a lot to chase here. It's not *terribly* uncommon
for an outdated server to appear in a list of NSs this long.
What *is* strange, is that your client would consider *choosing* an
outdated NS. It's also interesting to note the wide range in the
caches -- 3600 - 86400.

# drill -T bit.ly SOA
.	518400	IN	NS	a.root-servers.net.
.	518400	IN	NS	b.root-servers.net.
.	518400	IN	NS	c.root-servers.net.
.	518400	IN	NS	d.root-servers.net.
.	518400	IN	NS	e.root-servers.net.
.	518400	IN	NS	f.root-servers.net.
.	518400	IN	NS	g.root-servers.net.
.	518400	IN	NS	h.root-servers.net.
.	518400	IN	NS	i.root-servers.net.
.	518400	IN	NS	j.root-servers.net.
.	518400	IN	NS	k.root-servers.net.
.	518400	IN	NS	l.root-servers.net.
.	518400	IN	NS	m.root-servers.net.
ly.	172800	IN	NS	dns.lttnet.net.
ly.	172800	IN	NS	pch.ltt.ly.
ly.	172800	IN	NS	dns1.lttnet.net.
ly.	172800	IN	NS	ns-ly.afrinic.net.
ly.	172800	IN	NS	phloem.uoregon.edu.
bit.ly.	3600	IN	NS	ns-cloud-c2.googledomains.com.
bit.ly.	3600	IN	NS	ns-cloud-c3.googledomains.com.
bit.ly.	3600	IN	NS	ns-cloud-c1.googledomains.com.
bit.ly.	3600	IN	NS	ns-1372.awsdns-43.org.
bit.ly.	3600	IN	NS	ns-705.awsdns-24.net.
bit.ly.	21600	IN	SOA	ns-cloud-c1.googledomains.com. 
cloud-dns-hostmaster.google.com. 1 21600 3600 259200 3600
bit.ly.	86400	IN	NS	ns-1372.awsdns-43.org.
bit.ly.	86400	IN	NS	ns-276.awsdns-34.com.
bit.ly.	86400	IN	NS	ns-cloud-c4.googledomains.com.
bit.ly.	86400	IN	NS	ns-cloud-c3.googledomains.com.
bit.ly.	86400	IN	NS	ns-1766.awsdns-28.co.uk.
bit.ly.	86400	IN	NS	ns-cloud-c2.googledomains.com.
bit.ly.	86400	IN	NS	ns-705.awsdns-24.net.
bit.ly.	86400	IN	NS	ns-cloud-c1.googledomains.com.
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