Aggressive Chrony settings

[2072]

Hello,

First thank you for your guide!

I want to report that the suggested Chrony settings causes most servers to reply with tens of KoD packets per minute instead of replying with time data.

One can confirm this using the journalctl command, there will be hundreds of messages like this:

chronyd[9119]: Received KoD RATE from 91.189.89.199
chronyd[9119]: Received KoD RATE from 2001:67c:1560:8003::c8
chronyd[9119]: Received KoD RATE from 91.189.89.199
chronyd[9119]: Received KoD RATE from 2001:67c:1560:8003::c8
chronyd[9119]: Received KoD RATE from 91.189.89.199
chronyd[9119]: Received KoD RATE from 2001:67c:1560:8003::c8
chronyd[9119]: Received KoD RATE from 91.189.89.199
chronyd[9119]: Received KoD RATE from 2001:67c:1560:8003::c8
chronyd[9119]: Received KoD RATE from 91.189.89.199
chronyd[9119]: Received KoD RATE from 2001:67c:1560:8003::c8
chronyd[9119]: Received KoD RATE from 91.189.89.199

It doesn't sound right to set the minpoll and maxpoll to the same value. I've set mine to 2 and 10 respectively and I no longer have Received KoD RATE from... messages anymore.

pool time.google.com       iburst minpoll 2 maxpoll 10 maxsources 3 prefer
pool ntp.ubuntu.com        iburst minpoll 2 maxpoll 10 maxsources 3 maxdelay 0.3
pool time.nist.gov         iburst minpoll 2 maxpoll 10 maxsources 3 maxdelay 0.3
pool fr.pool.ntp.org       iburst minpoll 2 maxpoll 10 maxsources 3 maxdelay 0.3

You can get more details about those settings in Chrony.conf man page. I am not sure what are the optimal settings but polling time servers every 2 seconds constantly is probably not a good thing.