Traceroute explanation

Harsha V. Madhyastha harsha at cs.ucr.edu
Thu Dec 8 21:37:11 UTC 2011


Another explanation could be load balancing. As Fred mentioned, traceroute sends out different packets for different hops on the path and since these packets have different headers, load balancers on the path may hash packets with different TTL values on to different paths.

Check out http://www.paris-traceroute.net/ for more information.

--Harsha

On Dec 8, 2011, at 1:23 PM, Fred Baker wrote:

> This is just a guess, but I'll bet the route changed while you were measuring it.
> 
> Traceroute sends a request, awaits a response, sends a request, ... Suppose that the route was
> 
> 172.28.0.1 -> 10.16.0.2
>           -> 41.200.16.1
>           -> 172.17.2.25
>           -> 213.140.58.10
>           -> 195.22.195.125
>           -> 4.69.151.13
>           -> 213.200.68.61
>           -> somewhere else
> 
> and after the test got that far, two systems got inserted into the path before level3, resulting in the route entering level3 at a different point, 4.69.141.249. What you now have is
> 
> 172.28.0.1 -> 10.16.0.2
>           -> 41.200.16.1
>           -> 172.17.2.25
>           -> 213.140.58.10
>           -> 195.22.195.125
>           -> unknown
>           -> unknown
>           -> 4.69.141.249
>           -> 77.67.66.154
>           -> and so on
> 
> The effect would be to get a result like this.
> 
> Next time you see something like this, suggestion: repeat the traceroute and see what you get.
> 
> 
> On Dec 7, 2011, at 12:12 PM, Meftah Tayeb wrote:
> 
>> Hey folks,
>> i see a strange traceroute there
>> 
>> Détermination de l'itinéraire vers www.rri.ro [193.231.72.52]
>> avec un maximum de 30 sauts :
>> 
>> 1     2 ms     1 ms     1 ms  172.28.0.1
>> 2     1 ms     1 ms     1 ms  localhost [10.16.0.2]
>> 3    10 ms    10 ms    13 ms  41.200.16.1
>> 4    11 ms    10 ms    11 ms  172.17.2.25
>> 5    21 ms    21 ms    21 ms  213.140.58.10
>> 6    34 ms    31 ms    55 ms  pos14-0.palermo9.pal.seabone.net [195.22.197.125
>> ]
>> 7    34 ms    33 ms    35 ms  ae-5-6.bar2.marseille1.level3.net [4.69.151.13]
>> 8   106 ms    68 ms    67 ms  xe-1-1-0.mil10.ip4.tinet.net [213.200.68.61]
>> 9    74 ms    73 ms    74 ms  ae-1-12.bar1.budapest1.level3.net [4.69.141.249]
>> 10    63 ms    63 ms    79 ms  euroweb-gw.ip4.tinet.net [77.67.66.154]
>> 11    85 ms    84 ms    84 ms  v15-core1.stsisp.ro [193.151.28.1]
>> 12   100 ms   100 ms   102 ms  inet-crli1.qrli1.buh.ew.ro [81.24.28.226]
>> 13    81 ms    81 ms    81 ms  193.231.72.10
>> 14    92 ms    92 ms    93 ms  ip4-89-238-225-90.euroweb.ro [89.238.225.90]
>> 15    89 ms    89 ms    89 ms  webrri.rri.ro.72.231.193.in-addr.arpa [193.231.7
>> 2.52]
>> Itinéraire déterminé.
>> C:\Documents and Settings\TAYEB>
>> Seabone, then level3, then Tinet, then level3, then tinet ?
>> if is that a routing stufs that i don't know, please let me know :)
>> i never saw that befaure
>> 
>>   Meftah Tayeb
>> IT Consulting
>> http://www.tmvoip.com/ 
>> phone: +21321656139
>> Mobile: +213660347746
>> 
>> 
>> __________ Information from ESET NOD32 Antivirus, version of virus signature database 6695 (20111208) __________
>> 
>> The message was checked by ESET NOD32 Antivirus.
>> 
>> http://www.eset.com
>> 
> 
> 





More information about the NANOG mailing list