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In the plot below it is seen that following the initial earthquake the performance degraded (i.e. longer RTTs). The lack of measurements on May 5 and 6 is since the monitoring host at SLAC was being upgraded and did not make any measurements.
FAQ
Why is there no data from for www.nren.net.np from 0842-1143 on April 15th.
- The data gap from 08:42-11:43 is that the monitor at SLAC sent up to 30 pings at roughly each half hour until it received 10 ping responses. However there were no ping responses (i.e. 100% loss). Thus the NNREN web site was not reachable (could be the host crashed, or the network was no longer forwarding the packets, more likely the former given other information you refer to) and ping reports 100% loss.
The event occurred at 0611UTC, and for 2.5 hours(!) the connectivity from SLAC to NNREN was maintained quite well, it seems.
- I agree it is very interesting/curious that the connectivity appeared to continue working for 2.5 hours, and then died. One would need to talk to the net and host admins. There are many possibilities (e.g. maybe the network continued to work but a UPS on the host ran out of battery power, or the backup generator ran out of fuel, or people deliberately shut down power.
There is a second gap in the www.most.gov.np on 25 April from 1309-1939UTC, for which a similar question arises about the gap source.
The 25 April from 1309-1939UTC gap for www.most.gov.np is interesting in that the SLAC monitor was running fine based on measurements to the rest of the world. One would have expected it to have recorded 100% loss (i.e. unreachable), instead the software reports no measurement. This because the ping command itself failed to produce anything intelligible. I am not sure why. Unfortunately we do not retain the error logs that long.