19.3.2017, 22.01, Dewangga Bachrul Alam kirjoitti:
Hello Anssi,
Would you like to share how Cent OS team determine the mirror location by an IP address? Let's pick an example, softlayer has an IP test on Mexico (speedtest.mex01.softlayer.com), but yes, the traffic is through US than directly to Mexico. Possible it's IP Transit, since MIE (Mexico Internet Exchange) have same traceroute details.
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The good news is, I can get result from atlas probe, 10 probes on mexico are active.
Measurements to 204.45.61.61 https://atlas.ripe.net/measurements/7930303/#!probes
Measurements to mie.mx https://atlas.ripe.net/measurements/7930313/#!probes
Any hints from traceroute above? Hope it helps.
Notes: Is there any FAQ from mirror team about choosing mirror location determine by an IP Address? Correct me if I'm wrong.
The short answer is: It depends.
Longer answer: When Massachusetts Institute of Technology submitted their mirror to the list, it was pretty clear that the mirror was actually in Massachusetts. For some other mirrors we may do a quick lookup from one of the GeoIP providers out there, such as MaxMind. If everything matches, good, otherwise we may dig deeper. There are no particular guidelines for us at this stage, because the actions depend on the observed discrepancies. Usually asking for a clarification from the mirror submitter is enough, and we can usually reach a consensus of the mirror's location that way.
I'm unsure how relevant mie.mx is for this discussion, so I'm not commenting on that at this stage. However, while researching for this discussion, I have found that Mexico's ISP are (still) less interconnected than in some other countries. It is very well possible that some Mexican ISPs communicate with each other by passing their packets twice across the U.S. border. Hence my question about which Mexican ISPs centos.mexico.machost.co's host peers with, as that might shed some light on the observed oddities.
Thanks for the Atlas probes, I had entirely forgotten about that. I think it's noteworthy that all those 10 probes from Mexico to 204.45.61.61 ended up getting routed to Denver. This reinforces my view that the mirror does not seem to have a local network presence in Mexico. It looks like it's entirely in U.S., but as Mach Host claims otherwise, I'm listening to their input on this matter.
As for a FAQ, no, this does not come up frequently enough to warrant a FAQ entry. We generally expect mirror admins to know where their servers are, but we check the data they submit to make sure there aren't errors. In this age of "everything's in the cloud and nobody sees physical servers any more", the mirror admins might not even know where their servers are. It happens, but we try to work out the differences.