# Network: i/o timeout **URL:** \ **Category:** Server operators\ **Tags:** monitoring\ **Created:** [October 14, 2024, 1:59pm UTC](https://community.ntppool.org/t/network-i-o-timeout/3553 "2024-10-14T13:59:01Z")\ **Posts on this page:** 14\ **Page:** 2
**Author:** ![Kets\_One](https://avatars.discourse-cdn.com/v4/letter/k/46a35a/32.png) [@Kets\_One](https://community.ntppool.org/u/Kets_One)\ **Post date:** [October 21, 2024, 10:00am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/22 "2024-10-21T10:00:49Z")
![image](https://us1.discourse-cdn.com/flex016/uploads/ntppool/original/2X/4/4aeec0b5205bcb6316d8303bbc1d6e19bddd0fd4.png) Please see a screenshot above for three servers (US, NL). ---
**Author:** ![StopDragon](https://avatars.discourse-cdn.com/v4/letter/s/d26b3c/32.png) [@StopDragon](https://community.ntppool.org/u/StopDragon)\ **Post date:** [October 21, 2024, 12:08pm UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/23 "2024-10-21T12:08:25Z")
I didn’t know that the first two letters on the server mean country! ---
**Author:** ![ebahapo](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/ebahapo/32/1152_2.png) [@ebahapo](https://community.ntppool.org/u/ebahapo)\ **Post date:** [October 21, 2024, 2:42pm UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/24 "2024-10-21T14:42:43Z")
How come you get the offset and the RTT? ---
**Author:** ![Kets\_One](https://avatars.discourse-cdn.com/v4/letter/k/46a35a/32.png) [@Kets\_One](https://community.ntppool.org/u/Kets_One)\ **Post date:** [October 22, 2024, 9:56am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/25 "2024-10-22T09:56:22Z")
Unsure. This is just standard functionality on NTP pool server management page. 🙂 ---
**Author:** ![StopDragon](https://avatars.discourse-cdn.com/v4/letter/s/d26b3c/32.png) [@StopDragon](https://community.ntppool.org/u/StopDragon)\ **Post date:** [October 22, 2024, 11:13am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/26 "2024-10-22T11:13:55Z")
I didn’t understand exactly. My ntp server is configured with GPS+PPS and gets time from PSM. ---
**Author:** ![stevesommars](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/stevesommars/32/2075_2.png) [@stevesommars](https://community.ntppool.org/u/stevesommars)\ **Post date:** [October 22, 2024, 9:56pm UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/27 "2024-10-22T21:56:29Z")
For the past 30 hours [time.ravnus.com](http://time.ravnus.com) shows very low jitter; typical of what I see from other GPS-based NTP servers. The offset is probably low, though we can’t be certain. There were a few brief instances where the time was in error by hundreds of milliseconds, possibly related to NTP server reset. ==\> Server accuracy isn’t a likely problem. The RTTs I see from my monitors are consistent with those reported by [Kets\_One](https://community.ntppool.org/u/Kets_One) United Kingdom 236 msec RTT Germany 220 msec India 181 msec New York 181 msec San Francisco 138 msec Chicago 176 msec Ohio (US) 170 msec ==\> Latency isn’t a likely problem. [Note: my monitors are not part of the NTP Pool] There are significant NTP failures (request sent, but no response seen). For example my monitor in Germany saw 10% failures between 2024-10-21 14:00 and 2024-10-22 11:00. ==\> These failures are a problem. Troubleshooting is complicated by the intermittent use of Geoblocking. I don’t see how Geoblocking can be robustly implemented in the current NTP Pool. There are techniques to isolate the NTP loss. Running 24-hour tests from clients within Korea would be a start ---
**Author:** ![PoolMUC](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/poolmuc/32/1473_2.png) [@PoolMUC](https://community.ntppool.org/u/PoolMUC)\ **Post date:** [October 23, 2024, 3:15am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/28 "2024-10-23T03:15:44Z")
> [@stevesommars](#): > > Running 24-hour tests from clients within Korea would be a start [https://atlas.ripe.net/measurements/80431128/](https://atlas.ripe.net/api/v2/measurements/80431128/results/?format=json) > [@stevesommars](#): > > Troubleshooting is complicated by the intermittent use of Geoblocking …as well as the blocking of ICMP echo requests. [https://atlas.ripe.net/measurements/80368493/](https://atlas.ripe.net/api/v2/measurements/80368493/results/?format=json) And still not knowing what HW/SW the NTP server is made up of, and what amount of traffic it is seeing during its brief stints in the pool. ---
**Author:** ![stevesommars](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/stevesommars/32/2075_2.png) [@stevesommars](https://community.ntppool.org/u/stevesommars)\ **Post date:** [October 23, 2024, 2:55pm UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/29 "2024-10-23T14:55:54Z")
I used traceroute-style probes to further investigate the paths. These showed losses very close to the server. ```auto UK Hop 100% 11 ICMP:TTL 10.44.255.211 100% 12 ICMP:TTL 100.71.53.182 / 100.72.74.226 95% 13 ICMP:TTL 175.117.50.8 (time.ravnus.com) 95% 14 NTP 175.117.50.8 (time.ravnus.com) New York Hop 100% 18 ICMP:TTL 10.44.255.157 100% 19 ICMP:TTL 100.71.53.182 / 100.72.74.226 93% 20 ICMP:TTL 175.117.50.8 (time.ravnus.com) 95% 21 NTP 175.117.50.8 (time.ravnus.com) ``` The loss seems to be at [time.ravnus.com](http://time.ravnus.com), or possibly one hop upstream. As [PoolMUC](https://community.ntppool.org/u/PoolMUC) suggests more information about the NTP server’s environment is needed to explore further. ---
**Author:** ![PoolMUC](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/poolmuc/32/1473_2.png) [@PoolMUC](https://community.ntppool.org/u/PoolMUC)\ **Post date:** [November 2, 2024, 10:12am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/30 "2024-11-02T10:12:22Z")
Do you still have a publicly available stratum 1 server in South Korea? I’ve set up an instance in a datacenter in Seoul, and am looking for good upstream servers. I note [time.ravnus.com](http://time.ravnus.com) still serves time, but is at stratum 4 currently. Thanks! ---
**Author:** ![StopDragon](https://avatars.discourse-cdn.com/v4/letter/s/d26b3c/32.png) [@StopDragon](https://community.ntppool.org/u/StopDragon)\ **Post date:** [November 2, 2024, 10:48am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/31 "2024-11-02T10:48:34Z")
Yes, I’m still running. I deleted it in the ntp pool for a while because I’m changing the ISP on the 14th. I just checked and I think it’s because the PPS signal is not normal and the ntp server is using another source. I think I touched something while upgrading the equipment yesterday. I’ll check again tomorrow and let you know. ---
**Author:** ![StopDragon](https://avatars.discourse-cdn.com/v4/letter/s/d26b3c/32.png) [@StopDragon](https://community.ntppool.org/u/StopDragon)\ **Post date:** [November 2, 2024, 11:00am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/32 "2024-11-02T11:00:51Z")
I forgot to set up the gpio pin yesterday while upgrading the hardware to the raspberry pi 5 nvme ssd. Now I’m using the PPS signal normally. It will be referred to Stratum 1. ---
**Author:** ![PoolMUC](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/poolmuc/32/1473_2.png) [@PoolMUC](https://community.ntppool.org/u/PoolMUC)\ **Post date:** [November 2, 2024, 11:12am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/33 "2024-11-02T11:12:19Z")
Thanks!! Looking very good, with `chronyd` right away replacing the cloud-provided NTP server with yours as upstream: ```auto MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^* time.ravnus.com 1 6 377 37 +116us[+121us] +/- 750us ``` ```auto Name/IP Address NP NR Span Frequency Freq Skew Offset Std Dev ============================================================================== time.ravnus.com 10 6 581 +0.000 0.201 +8ns 26us ``` Let’s see what it looks like once `chronyd` has settled in and, e.g., ramped up the polling interval… 🙂 ---
**Author:** ![StopDragon](https://avatars.discourse-cdn.com/v4/letter/s/d26b3c/32.png) [@StopDragon](https://community.ntppool.org/u/StopDragon)\ **Post date:** [November 20, 2024, 10:30am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/34 "2024-11-20T10:30:55Z")
Not long ago, I changed my ISP. I duplicated the ntp server from Statum 1 to Statum 2. Statum 1 is accessible only in our local, and Statum 2 server synchronized in the same local to provide ntp service to external users so that it can be more stable. Statum 2 servers have better RAM and CPU performance than traditional Statum 1. For those who use our server in Asia, please check if our server is running reliably! ---
**Author:** ![system](https://sea2.discourse-cdn.com/flex016/user_avatar/community.ntppool.org/system/32/1_2.png) [@system](https://community.ntppool.org/u/system)\ **Post date:** [December 20, 2024, 10:31am UTC](https://community.ntppool.org/t/network-i-o-timeout/3553/35 "2024-12-20T10:31:29Z")
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