«When you add or change DNS zones or records, your changes will now be
reflected at our authoritative nameservers in under 60 seconds. This is
down from the previous “every quarter hour” approach that we had for so
long.» - https://www.linode.com/blog/linode/linode-turns-17/
Using the default value of 16 minutes (960 seconds) for
--dns-linode-propagation-seconds leads to DNS failures when the randomly
selected Linode DNS is not the first one out of six, due to an additional
delay before the other five are updated.
The problem can be easily solved by increasing the wait interval, so
this commit increases the default value to 20 minutes.
More details: https://community.letsencrypt.org/t/dns-servers-used-by-letsencrypt-for-challenges/32127/16
Ștefan Talpalaru