...
For each ping sent to www.cern.ch it responds with ~3 pings consistently. Using the normal traceroute www.cern.ch does not respond. Using the ICMP traceroute it does respond (twice). Pinging each node along the route using pingroute.pl (http:/http://www-dev.slac.stanford.edu/cgi-wrap/scriptdoc.pl?name=pingroute.pl) (unfortunately mtr does not report duplicates), it is seen that only www.cern.ch responds with duplicate packets.
Analysis of data in Jan 2015
We have data from PingER going back to 2005 which I have mined to look for DUP's. The input data is one line per set of pings made from SLAC to a remote host. The line indicates whether there were DUP’s.
Each line is for a remote host monitored from SLAC with up to 10 successful (with a cut off at 30 tries) 100 Byte pings each 30 mins.
We wrote a perl script (dupes.pl) to analyze the data.
The monitoring host (pinger.slac.stanford.edu) is not using multicast, the interfaces are not bonded. It is running Linux:
Linux pinger 2.6.32-279.19.1.el6.i686 #1 SMP Sat Nov 24 14:42:18 EST 2012 i686 i686 i386 GNU/Linux
The current number of countries with remote hosts being monitored is 171.
The major contributor since 2006 has been www.cern.ch, each year we see about 60 different hosts responding with DUPs.
A list of the hosts responding with DUP pings in 2014 is below, followed by a summary of the annual DUP pings.
List of hosts responding with DUPlicate pings in 2014
2014: cbinet.bi seen duping 35 times
2014: internet.fo seen duping 6 times
2014: ms01.linea.gov.br seen duping 1 times
2014: ns.conacyt.gob.sv seen duping 3 times
2014: ping.cern.ch seen duping 450 times
2014: pinger.daffodilvarsity.edu.bd seen duping 2 times
2014: pinger.ictp.it seen duping 1 times
2014: pinger.numl.edu.pk seen duping 96 times
2014: pingerqta.pern.edu.pk seen duping 1 times
2014: www.acgrc.am seen duping 2 times
2014: www.afribone.net.gn seen duping 2 times
2014: www.afrinet.cd seen duping 8 times
2014: www.aic.ac.nz seen duping 1 times
2014: www.alard.ps seen duping 1 times
2014: www.bonesha.bi seen duping 73 times
2014: www.boz.zm seen duping 4 times
2014: www.cern.ch seen duping 14026 times
2014: www.cnrst.bf seen duping 43 times
2014: www.cyfronet.krakow.pl seen duping 1 times
2014: www.drtvnet.cg seen duping 12 times
2014: www.eritel.com.er seen duping 373 times
2014: www.gov.bw seen duping 635 times
2014: www.granma.cu seen duping 9 times
2014: www.hraparak.am seen duping 1 times
2014: www.ihep.su seen duping 1 times
2014: www.kcn.unima.mw seen duping 118 times
2014: www.lanl.gov seen duping 1 times
2014: www.lonab.bf seen duping 394 times
2014: www.lsx.com.la seen duping 1 times
2014: www.minzdrav.uz seen duping 12 times
2014: www.ml.refer.org seen duping 1 times
2014: www.nomad.mu seen duping 1 times
2014: www.rmutsv.ac.th seen duping 4 times
2014: www.rub.edu.bt seen duping 1 times
2014: www.stmaryuniversitycollege.edu.et seen duping 1 times
2014: www.uniswafoundation.org.sz seen duping 1 times
2014: www.univ-koudougou.bf seen duping 632 times
2014: www.univ-ouaga.bf seen duping 7 times
2014: www.uns.ac.id seen duping 2 times
2014: www.vnu.edu.vn seen duping 26 times
2014: www.vnuhcm.edu.vn seen duping 1 times
Summary of yearly data of DUP pings
See spreadsheet.
Year | DUPs | Hosts DUPing | Hosts monitored | Samples | % | CERN | Diff | % CERN |
2005 | 93 | 27 | 481 | 11408092 | 0.0008% | 0 | 93 | 0.00% |
2006 | 9228 | 40 | 514 | 13715929 | 0.0673% | 5751 | 3477 | 62.32% |
2007 | 35673 | 42 | 541 | 16315320 | 0.2186% | 34721 | 952 | 97.33% |
2008 | 39262 | 57 | 592 | 19680482 | 0.1995% | 34249 | 5013 | 87.23% |
2009 | 42356 | 52 | 663 | 17889767 | 0.2368% | 27469 | 14887 | 64.85% |
2010 | 74638 | 51 | 623 | 19862304 | 0.3758% | 19693 | 54945 | 26.38% |
2011 | 30769 | 79 | 659 | 22889278 | 0.1344% | 22518 | 8251 | 73.18% |
2012 | 85217 | 50 | 797 | 23786399 | 0.3583% | 34402 | 50815 | 40.37% |
2013 | 74128 | 76 | 774 | 25475771 | 0.2910% | 34916 | 39212 | 47.10% |
2014 | 16990 | 41 | 836 | 29933696 | 0.0568% | 14026 | 2964 | 82.55% |
2015 | 164 | 4 | 514773 | 0.0319% | 104 | 60 | 63.41% |