level3_bx4-montrealak.net consistently dropping 50% of the packets

Hello Everyone,

According to mtr command we are consistently seeing
dropping 30-50% of packets. Our ISP is Bell Canada. Any ideas on how to get
this resolved are greatly appreciated.

HOST: victoria Loss% Snt Last Avg Best Wrst StDev
  1.|-- 0.0% 10 0.5 0.8 0.4 1.6 0.5
  2.|-- lns2-montrealak_lo0_LNS.n 0.0% 10 6.7 7.6 6.7 8.8 0.7
  3.|-- agg1-montrealak_GE0-2-2_1 0.0% 10 6.4 6.3 5.4 7.6 0.6
  4.|-- bx4-montrealak_so-0-0-0.n 0.0% 10 6.0 5.8 4.9 7.0 0.7
  5.|-- level3_bx4-montrealak.net 50.0% 10 6.5 6.7 5.7 7.9 0.8
  6.|-- ae-11-11.car1.Montreal2.L 0.0% 10 92.2 91.7 91.0 92.8 0.7
  7.|-- ae-5-5.ebr2.NewYork1.Leve 0.0% 10 90.9 92.0 90.9 92.7 0.6

Kind Regards,


Since you dont see packet loss on the subsequent hops, this is likely

just ICMP rate limiting on the control plane. MTR

sends quite a bit of ICMP so this is very common when using MTR.

Not a "possible" reason for the degradation of voip from us to our service
Is there a more accurate test that will render more explanation?

Thanks for the prompt Chris.

It's dropping packets _to_ and/or _from_ it.
Seem it's got the priorities well adjusted and does not drop packets being
_forwarded_ (see hops 6 and 7).

first $search_engine hit for me was


There are reports of problems in Montreal with several other providers over the last several days. These seem to coincide with the Olympics live broadcasts, particularly during the hockey broadcasts.

-- Stephen

A careful reading of the following fixes this issue every time it
occurs. I guarantee it.


Makes even more sense when you're a CS student working on getting your PPL :wink:


I you do not see as high or higher packet loss reported at the hops after, all you are seeing is control plane filtering / rate limiting on that router.

Thank you all for clarifying. Really appreciate it.