This weekend I replaced my ten year old Xeon based Stratum 1 server with a Stratum 1 server based on the Raspberry Pi. I am very happy with the power usage going back from 89 Watt to just a few Watt The reference clock didnāt change: it is still the original Garmin 18LVC GPS. I used chronyd instead of ntpd because it was pre-installed in the Linux image I used. The image is the Centos 7 ARM image BTW, not the more common Raspbian image because all my Linux servers are Centos based and I like to use the same tools and configuration on all servers independent on the underlying hardware.
As the new server supports IPv6, I also wanted to add this address to the pool. When adding the server domain name ntp4.ipv6.linocomm.net to the pool, the system however responds with the message āCould not check NTP statusā.
I can access the NTP server over IPv6 from my other servers in the field, so basic connectivity doesnāt seem to be a problem. But so many things changed with the move from the old to the new server that it is somewhat difficult to track down the issue.
Any hints where I should start to debug this issue?
I tested this with ntp2.tdc.fi. Itās a dual-stacked NTP server but not in the pool (I had no intention to add it, of course), and looks like IPv4 testing works but IPv6 gives that āCould not check NTP statusā message. Iād say @ask will need to check this.
Whoops ā the upgrades this weekend moved the service thatās doing the checking. While moving it I did a new compile with upgraded dependencies, it looks like the IPv6 check broke. Iāll fix it tonight.
Oh, geez. I only tested the fix on my laptop. The particular server I moved this daemon to had a bungled network configuration from a while ago when we had trouble with a new firewall and were testing if it was an MTU problem (it wasnāt, but this particular system was left with a smaller MTU).
Iāve added monitoring for the trace.ntppool.org daemon to check that it can test v4 and v6 IPs.