Hi, i’v been operating a small NTP server with a GPS receiver antenna. In my country there are a few (4 ipv4 and 2 ipv6) and mine is one of those ipv4. The per-myriad statistic shows some numbers, is there anyway to estimate the NTP/day queries the server is handling? I have a hard time to estimate this number. Maybe with the total queries per country i can get an approximate number. Thanks!
Well, sorry, it’s very hard to predict.
But I use this software to show me what’s going on.
If there are just a few servers, it may be hit hard.
But no way of knowing until you check it like I did.
When the numbers are high, you can ask people in here to step in and help devide the load.
But as you didn’t show your server page, it hard to say more.
See my Belgian server… pool.ntp.org: Statistics for 185.142.225.68
The easiest and most reliable way is to query your NTP server software:
# chronyc -n serverstats
NTP packets received : 16049704023
Then repeat this same command after some time (like one hour or one day) and calculate the difference.
What i have is pfSense data on port 123
12.653K/29.08GiB
Evaluations 156.599M
Packets 410.47M
Bytes 29.08GiB
States 12.653K
Rule Created 7/24/25 19:37:16 by NAT Port Forward
Maybe i could estimate some order of magnitude from these numbers? I would need to know how many bytes does a NTP packet has, right?
1 Like
Standard IPv4 NTP response packet is typically 76 bytes at the IP layer. This size includes the UDP and NTP headers but excludes lower-level headers like Ethernet framing. When including Ethernet headers, the total frame size is often around 90 bytes.
Using 90 bytes this translates to ~160 million requests incoming and ~160 million outgoing replies.
The question is what the timeframe is over which the 29GB was accumulated.
If the rule creation date is the start of the counting, then ~12,000,000 seconds elapsed.
161,000,000 / 12,000,000 = 13 requests per second; a modest amount by most standards.
Great analysis, thanks. The server i run is pool.ntp.org: Statistics for 200.40.115.74 and it’s values of % per myriad are:
Global points 1.909‱
Top Countries
uy 1862.509 ‱ 7352.941 ‱ (0.25x)
br 0.482 ‱
ar 1.236 ‱
us 0.038 ‱
bo 11.281 ‱
Is this 18% of ntppool.org for Uruguay?, that seems a lot to me. Maybe i’m mis-interpreting the number.
The server hardware specifications say about 1000 queries/second, so with 13 per second it’s in the super safe zone.
With four IPv4 servers in the Uruguay zone 18% seems to be in the right ballpark.
Look to me you are feeding 20% of the country of time, that is a very huge load.
As your pFsense also shows.
As your ‘pool’ shows: Zones: @ south-america uy ✓
It looks to me you should lower the ‘speed setting’ to 512kbit or 1mbit, then a you serve less (not world!) and it should reduce the load a lot.
It will still be high, but drop.
If it doesn’t change that much, as other servers to help you feeding UY.
As you are now feeding BO a lot too. If you can handle this load, you are fine, when not, lower the speed.