I have run half off all the NTP servers in Costa Rica for many years now. These servers serve hundreds of devices on the internal ISP network they are part of and thousands more outside. Almost 2 months ago the responses they give don’t get logged or don’t reach the Los Angeles monitoring Station. T…

I have some pool servers in Europe and one of them is also monitoring a subset of other pool servers. I have some data for 200.59.16.50. It seems over the last six months the reachability was 97.4%. I think that’s pretty good. It’s actually slightly better than reachability of the IPv6 address of th…

[image] That server in particular is a Stratum 1 and NTP is his only job. He had a hardware problem beginning February and was taken out for a complete hardware upgrade during March, during that time a Stratum 2 server answered the queries. So yes 97 % is for sure right considering all the hardware…

I did some traffic engineering and now send the reply using a different upstream provider. [image] The problem seems to be completely gone. But I wonder if it’s just packet loss via that link or something else. I still think that having at least 3 monitoring stations is critical for having a bette…

This is great. Can you tell what the upstream provider change was? I wonder if they are blocking (some?) NTP packets…

The old upstream route towards the monitor went: root@stratum1:~# traceroute 207.171.3.17 traceroute to 207.171.3.17 (207.171.3.17), 30 hops max, 60 byte packets 1 ether3.mikrotik-bb-zeus.fratec.net (200.59.16.33) 0.189 ms 0.160 ms 0.133 ms 2 sfp-sfpplus1.mikrotik-bb-router-gnd1.fratec.net …

I’ve had problems recently with ipv4 UDP (incl NTP and DNS) transit through AS6939 “Hurricane Electric LLC” - my short story is written here: [image] Monitoring station seems to hate my server all of a sudden Server operators In case somebody still has issue wi…

When did all of the dropping begin? I was just kinda wondering if it is a result of the Ntp reflection issue that occurred.

In my case, HE tunnel problems began at the end of February, and by the middle of March I just killed the BGP session since it was not getting better. For now native IPv6 traffic is going fine to Los Angeles Monitoring Station but IPv4 not so. [image]

Had this issue recently at different times with different servers, which are not part of the pool. Our monitoring system got no answer to NTP questions, so I started capturing traffic on both ends. The NTP server sent a valid reply, but this got just lost. Other UDP services on the same machine we…

Problems with the Los Angeles IPv4 monitoring Station

Server operators

konrad.jedrzejczyk April 3, 2019, 12:14pm 7

I’ve had problems recently with ipv4 UDP (incl NTP and DNS) transit through AS6939 “Hurricane Electric LLC” - my short story is written here:

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Problems with the Los Angeles IPv4 monitoring Station

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