How do I flush the DNS cache on a Linode? Its not updated yet
I updated DNS of a domain a while ago. Its updated externally to Linode for some time.
But on my mail server, the domain's MX record is still pointing to the old IP. So when I send the domain mail, its still going to the old IP.
I imagine the Linode DNS is not updating as quick as the TTLs?
Anyway to force an update/flush?
It depends on what your TTL is set to on the domain. It’s likely being cached on Linode’s DNS resolvers (the DNS servers your Linode uses to lookup records, which are different to the master DNS servers.)
If your Linode had recently looked up the record, it will be cached for the TTL on Linode’s resolvers.
External resolvers that haven’t recently looked up the record would see the updated record as it wouldn’t have had it cached and would have gone back to the source (Linode master.)
The only course of action I can think is to temporarily change your resolvers to something like Google (184.108.40.206, 220.127.116.11) or Cloudflare’s (18.104.22.168, 22.214.171.124) until a point you know the record has expired on Linode’s resolvers.
I am not sure of the TTL. I actually changed nameservers back to my domain provider, and they updated at Mxtoolbox, Whatsmydns, WHOIS, pinging from my home within 5 mins.
But its on my Linode its not. Still isn't now about 5 hours later.
Have changed the DNS servers on the Linode to Google's and it worked right away.