I was going to reply and repeat Job Snijders's indications of Thu, 7 Jul 2016 to Please review the excellent presentation from RA{T,S}: https://www.nanog.org/meetings/nanog47/presentations/Sunday/RAS_Traceroute_N... https://www.youtube.com/watch?v=a1IaRAVGPEE esp the pdf there, but in this case Randy's mtr does do a ping to the last hop. He did have 4.1% pl to the endpoint for his specific setup and current gear/route/etc. However, I go through the same hostname'd router he does (he didnt provide an ip, but paris-traceroute doesnt show me load balancing, at least visibly), and I only get 0.3% pl. (Though, my immediate upstream DSL provider's router is giving me 0.2% pl, so who knows what that 0.3% means at the far end, really.) Without bidirectional concurrent mtr's (one from cogent back to him at the same time), it's quite hard to say what's going on. Even then that's no guarantee of diagnosis. Here's just the most recent thread with some depth on how to read traces and packetloss: http://seclists.org/nanog/2016/Jul/155 the whole thread is useful. But is only one of the dozens of times this has come up on nanog. (Again: read that pdf!) /kc On Wed, Dec 14, 2016 at 05:53:56PM -0200, Kurt Kraut said:
Hello,
mtr packet loss column has no scientific precision and should not be considered. It is not mtr fault but forwarding routers have a low priority to respond to ICMP requests. The only way you can prove there is a problem is a end to end ping, the regular ping command, not mtr.
Best regards,
Kurt Kraut
2016-12-14 17:16 GMT-02:00 Randy <amps@djlab.com>:
Hi all,
Anyone beyond front line support at cogento on list?
Nanog is the last place I'd look for assistance but it seems support over at cogentco is not nearly what it used to be.
Example MTR to cogen't own website (support doesn't utilize or understand MTR at all apparently):
Host Loss% Snt Last Avg Best Wrst StDev 1. x.x.x.x 0.0% 196 0.5 11.7 0.3 186.8 35.2 2. x.x.x.x 0.0% 196 0.6 10.2 0.4 226.3 36.2 3. 38.88.249.209 0.0% 196 0.9 1.1 0.7 17.7 1.2 4. te0-0-2-3.nr13.b023801-0.iad01.atl 0.0% 196 1.0 1.0 0.8 2.0 0.1 5. te0-0-0-1.rcr22.iad01.atlas.cogent 2.0% 196 2.1 1.9 1.0 3.3 0.4 6. be2961.ccr41.iad02.atlas.cogentco. 2.6% 196 1.8 2.1 1.1 3.8 0.5 7. be2954.rcr21.iad03.atlas.cogentco. 2.6% 196 2.0 2.3 1.2 9.4 0.7 8. be2952.agr11.iad03.atlas.cogentco. 0.5% 196 2.7 2.6 1.5 6.8 0.6 9. cogentco.com 4.1% 196 2.1 2.0 1.0 16.8 1.1
Pretty much the same to anywhere. Packet loss begins at rcr22.iad01 and propagates all the way down the line. Worse during peak hours, gone late at night.
After three days of no email response for my ticket, I called and after an hour of my life I want back, front line support cannot reproduce the loss. Final conclusion: "Your host is dropping packets".
-- ~Randy
-- Ken Chase - math@sizone.org Guelph Canada