Algo Node stopped syncing at 2.5.6 and resolved

@fabrice Could you please help me understand below issue .

My node stopped syncing which was running at 2.5.6 .

  1. I checked node.logs for find the root cause found DNS Look up issue for which ib have searched over the forum and it was instructed to run the dig command which i did - dig @ srv and below is the output

; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> @ srv
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached

I guess with the DNS lookup and dig command i thought its something with the 2.5.6 node. Can you please confirm my understanding.

But i could not find a way but to upgrade the algo node to 2.7.1 and everything starts working.

After that again i took a look at the logs

  1. I still have the DNS look up issue and
  2. dig command returns the same

Can you please let me know what are the above 2 issues all about and i guess these were not the real reasons for node stopped syncing .So what might the reason for the node sync issue and how can we find the root cause moving ahead

The main issue was the fact the node was outdated. You needed 2.7.1.

The fact that dig @ srv does not work means you cannot use (and most likely you cannot use DNSSec which reduces security).
But if the correct flag disabled DNSSec is in your config and if your node is syncing, there is nothing more to do.