Add sample

README.md

@@ -1,2 +1,47 @@
 # ripe-atlas-scripts
 Random scripts using RIPE Atlas API
+
+## root-reachability.py
+This scripts measures reachability to [K root server](https://www.ripe.net/analyse/dns/k-root/) from a given set of countries using DNS and Traceroute.
+Obviously the target as well as country list can be modified for your own measurements.
+
+Given that RIPE Atlas limits number of concurrent measurements toward the same destination, it yields error
+messages if your request is rate limited. The script keeps track of created measurements in "meas-ids.json" file
+in order to avoid creating duplicate measurements. You may want to re-run the script after a few minutes until all 
+the measurements are created. You may also want to remove the sample "meas-ids.json" file if you want to create
+your own set of measurements.
+
+Please note that you have to get your own API Key from [RIPE Atlas](https://atlas.ripe.net/) website and modify the script to use your API Key.
+
+Here is a sample measurement done using the script:
+
+```
+% ./root-reachability.py create
+- Created measurement for DK
+- Created measurement for NL
+- Created measurement for IE
+- Created measurement for DE
+- Created measurement for FR
+```
+
+Now loading DNS measurements, output in CSV:
+```
+% ./root-reachability.py load-dns
+cc, num_probes,  avg_rtt
+IE, 47, 42
+FR, 48, 42
+DE, 49, 49
+DK, 45, 44
+NL, 49, 21
+
+```
+And Traceroute measurements, output in CSV:
+```
+% ./root-reachability.py load-trace
+cc, num_probes,  num_hops
+DK, 47, 8
+NL, 50, 6
+IE, 47, 9
+FR, 50, 11
+```
+