Anyone from Verizon/TATA on here? Possible Packet Loss

Pellitteri Alexis alexis at pellitteri.com.ar
Wed Sep 26 19:18:43 UTC 2012


That router might be experiencing a high CPU load, thus not being able 
to reply ICMP on a timely manner or maybe QoS policies are influencing 
depending on the kind of traffic the router deals with.

If packets are only being delayed/lost on that segment, I would start my 
analysis there.

On 09/26/2012 04:02 PM, Jo Rhett wrote:
> Many (most?) routers deprioritize ICMP meesages. Direct pings against the router are not informative re transit failures.
>
> On Sep 26, 2012, at 11:37 AM, Derek Ivey wrote:
>> After some further troubleshooting, I believe I have narrowed down the issue to one of Verizon's routers (130.81.28.255).
>>
>> ping 130.81.28.255 repeat 100
>> Type escape sequence to abort.
>> Sending 100, 100-byte ICMP Echos to 130.81.28.255, timeout is 2 seconds:
>> ?!!!!!!!!?!!!!!!!?!!!!!!!!?!!!!!!!!!!!!!!!?!!!!!!!!!!!!!!?!!!!!!!!!!!?
>> !!!!!!!!!!!!!!!!!!!!!!?!!!?!!!
>> Success rate is 91 percent (91/100), round-trip min/avg/max = 20/26/30 ms
>>
>> I had my client send me the output of the ping command (100 pings) and a trace route.
>>
>> Their 5th hop is 130.81.28.254 and one of the response times in their trace route was 175ms so the issue seems to be around there.
>>
>> I asked them to open a ticket with Verizon to take a look.
>>
>> Thanks,
>> Derek
>>
>> On Sep 26, 2012, at 1:54 PM, Derek Ivey <derek at derekivey.com> wrote:
>>
>>> Thanks guys. That was an informative read. I will do some more troubleshooting.
>>>
>>> Derek
>>>
>>> On Sep 26, 2012, at 1:16 PM, Darius Jahandarie <djahandarie at gmail.com> wrote:
>>>
>>>> On Wed, Sep 26, 2012 at 1:10 PM, Blake Dunlap <ikiris at gmail.com> wrote:
>>>>> This is not the proper way to interpret traceroute information. Also, 3
>>>>> pings is not sufficient to determine levels of packet loss statistically.
>>>>>
>>>>> I suggest searching the archives regarding traceroute, or googling how to
>>>>> interpret them in regards to packet loss, as what you posted does not
>>>>> indicate what you think it does.
>>>> Agreed. Derek should read "A Practical Guide to (Correctly)
>>>> Troubleshooting with Traceroute":
>>>> http://www.nanog.org/meetings/nanog45/presentations/Sunday/RAS_traceroute_N45.pdf
>>>>
>>>> -- 
>>>> Darius Jahandarie
>>




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