<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style> </head> <body dir="ltr"> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> Thanks Robert</div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> </div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> I am using the probe estimated geolocations to validate a new active geolocation method I am formulating.</div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> The probe I that I thought had an anomaly was in fact found to be within 1k distance of my estimated geo location using the new method. The original discrepancy was due to a number of factors that I had failed to accurately apply.</div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <br> </div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> However, I have other probes that have similar but different issues and whilst I am working my way through these issues a<span style="background-color:rgb(255, 255, 255);display:inline !important">ny additional information you can provide would be greatly appreciated. </span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <span style="background-color:rgb(255, 255, 255);display:inline !important"><br> </span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <span style="background-color:rgb(255, 255, 255);display:inline !important">Regards</span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <span style="background-color:rgb(255, 255, 255);display:inline !important"><br> </span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <span style="background-color:rgb(255, 255, 255);display:inline !important"><br> </span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <span style="background-color:rgb(255, 255, 255);display:inline !important">Paul McCherry</span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <span style="background-color:rgb(255, 255, 255);display:inline !important">Phd Student</span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> <span style="background-color:rgb(255, 255, 255);display:inline !important">Lancaster University.</span></div> <div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> </div> <div> <div id="appendonsend"></div> <div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"> <br> </div> <hr tabindex="-1" style="display:inline-block; width:98%"> <div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Robert Kisteleki <robert@ripe.net><br> <b>Sent:</b> 25 March 2021 12:47<br> <b>To:</b> Mccherry, Paul (Student) <p.mccherry@lancaster.ac.uk>; ripe-atlas@ripe.net <ripe-atlas@ripe.net><br> <b>Subject:</b> [External] Re: [atlas] Probe location obfuscation</font> <div> </div> </div> <div class="BodyFragment"><font size="2"><span style="font-size:11pt"> <div class="PlainText">This email originated outside the University. Check before clicking links or attachments.<br> <br> Hi,<br> <br> On 2021-03-25 13:00, Ponikierski, Grzegorz via ripe-atlas wrote:<br> > I would add to it additional problem that some hosts obfuscate probe<br> > location even more. For example you can find probes which in reality are<br> > located in US but are marked as CN or probes which are in reality in<br> > Wisconsin but are marked in California. Of course these are extreme<br> > cases. I guess most hosts just put a pin with probe location just<br> > somewhere around where it's locate as long it's in the same city. I<br> > don't remember, as a host of 3 probes, to get any precise<br> > recommendations how to mark probe location. Personally I just put a pin<br> > in city district where probe is locate.<br> <br> We don't have strict rules about precisely how the hosts should<br> geolocate their probes -- and could not enforce those even if we had<br> them. Instead we recommend doing this "roughly correct", which for some<br> hosts means city / neighbourhood is good enough, for some others it's<br> the exact spot of the utility box at home :-)<br> <br> > Can anyone confirm the geo-location obfuscation of probes as being up to<br> > 1km as per<br> > <a href="https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fatlas.ripe.net%2Fabout%2Ffaq%2F%23are-the-locations-of-probes-made-public&data=04%7C01%7Cp.mccherry%40lancaster.ac.uk%7C0d707df0f3534cd8707008d8ef8c2bb3%7C9c9bcd11977a4e9ca9a0bc734090164a%7C0%7C1%7C637522732594157947%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ZRNBZBO61oUXTYZGVYNyfyNRG2J4sv4AIrchzrCitOg%3D&reserved=0"> https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fatlas.ripe.net%2Fabout%2Ffaq%2F%23are-the-locations-of-probes-made-public&data=04%7C01%7Cp.mccherry%40lancaster.ac.uk%7C0d707df0f3534cd8707008d8ef8c2bb3%7C9c9bcd11977a4e9ca9a0bc734090164a%7C0%7C1%7C637522732594157947%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=ZRNBZBO61oUXTYZGVYNyfyNRG2J4sv4AIrchzrCitOg%3D&reserved=0</a> <<a href="https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2Fatlas.ripe.net%2Fabout%2Ffaq%2F*are-the-locations-of-probes-made-public__%3BIw!!GjvTz_vk!EWq0OCOmS-1Af9zWmGzygQZxC02O19msR11hqwe7X3bHqvxoqX8Tt17N3fDKNB4%24&data=04%7C01%7Cp.mccherry%40lancaster.ac.uk%7C0d707df0f3534cd8707008d8ef8c2bb3%7C9c9bcd11977a4e9ca9a0bc734090164a%7C0%7C1%7C637522732594157947%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=VdT77jYEFo5pWuPHqRjnowZPIq9neOLHKc%2B47slBNI8%3D&reserved=0">https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2Fatlas.ripe.net%2Fabout%2Ffaq%2F*are-the-locations-of-probes-made-public__%3BIw!!GjvTz_vk!EWq0OCOmS-1Af9zWmGzygQZxC02O19msR11hqwe7X3bHqvxoqX8Tt17N3fDKNB4%24&data=04%7C01%7Cp.mccherry%40lancaster.ac.uk%7C0d707df0f3534cd8707008d8ef8c2bb3%7C9c9bcd11977a4e9ca9a0bc734090164a%7C0%7C1%7C637522732594157947%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=VdT77jYEFo5pWuPHqRjnowZPIq9neOLHKc%2B47slBNI8%3D&reserved=0</a>><br> ><br> > I am a Phd student carrying out research on the RIPE atlas platform and<br> > an early result seems to indicate 1 probe has an obfuscation of 10km<br> > distance but this may be an anomaly or perhaps something not taken into<br> > account as yet.<br> <br> We have a very simple algorithm that does the obfuscation consistently<br> with a certain maximum distance added, which may not be precisely 1km.<br> We can talk offline about the details if you're really interested in the<br> precise method.<br> <br> Cheers,<br> Robert<br> </div> </span></font></div> </div> </body> </html>