tracert vs. tracetcp

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Jun 7th, 2010
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Anyone who can explain to me the below tracetcp and tracert that I have gathered. From hop 4-12 show high latency but at the end it shows low latency result, is this acceptable? why at middle show high latency values? Thanks

1       1 ms    1 ms    1 ms

2       1 ms    1 ms    1 ms

3       51 ms   52 ms   50 ms

4       966 ms  1206 ms 1039 ms

5       1297 ms 1435 ms 1392 ms

6       951 ms  1113 ms 1036 ms

7       1093 ms 1023 ms 1201 ms

8       1169 ms 1308 ms 1077 ms

9       815 ms  644 ms  1034 ms   

10      815 ms  727 ms  869 ms 

11      589 ms  756 ms  669 ms

12      1045 ms 965 ms  748 ms

13      Destination Reached in 286 ms. Connection established to

Below is a simple diagram where tracetcp destination ip:443 from Network A to Network C was performed. A packet shaper is shaping the traffic from/to network A and from/to network C. Both Vlans traffic are shape in the shaper at network B.






Packet Shaper


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milan.kulik Mon, 06/07/2010 - 23:44
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here is an explanation how ICMP packets travel through the MPLS backbone when running traceroute:

(or for a .pdf version).

It shows why the result might be confusing showing long response time for routers in the middle of the path.



korbenda11as Tue, 06/08/2010 - 01:16
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Hi Milan,

Thanks for your answer and the link you gave, however, is there any much easy explanation on this? Is the traceroute or tracetcp results shows acceptable/normal?

I did a lot of traceroute test that traverses MPLS clouds but this is the first time that I have this kind of results. Is the shaper has something to do with this? Any other simple explanation on this? Thanks,

milan.kulik Tue, 06/08/2010 - 04:00
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the link I provided explains how the traceroute works through the MPLS cloud:

You either don't see the internal infrastructure (the second case in the document) or the response times are confusing as the ICMP packet is traversing the whole MPLS cloud back and force (the first case in the document and your case, too).

So in your case, the traceroute output reliable info is the path through the MPLS cloud and the number of hops.

The response times are misleading though (routers might also have some control plane policies configured to protect thier performance, see and the only important and reliable response time is that one from the target.

Any packet shaper on the path can also influence the response times depending on its configuration.




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