NYC to DEU packet loss

Trying to troubleshoot packet loss from NYC to DEU. Traceroute shows:

tdurack@2ua82715mg:~$ traceroute -I
traceroute to (, 30 hops max, 60 byte packets

4 ( 1.694 ms 1.698 ms 1.698 ms
5 ( 4.788 ms 4.792 ms 4.791 ms
6 ( 1.684 ms 1.461 ms 1.452 ms
7 ( 40.457 ms 42.980 ms 42.982 ms
8 hh-eb3-i.HH.DE.NET.DTAG.DE ( 129.417 ms * 129.422 ms
9 ( 139.501 ms 136.192 ms 139.236 ms

Packet loss of approx. 20% affects hops 7 and 8, along with end host
9. Loss appears to be data-plane, not control-plane rate limiting.
Affected customer confirms this too :slight_smile: is in Deutsche Telekom address spaces, so I'm guessing
this is either a DTAG problem or an issue between XO and DTAG.

I have a ticket open with XO, but I'm having a hard time figuring out
what is ~40ms away from NYC on a path to DEU. Any idea what the
physical path is?

You may cross check return path to XO if you have access to any sever on
DTAG or from there looking glass if available. In many cases sudden latency
spike comes because of incorrect return path.

Hope this will help.

Anurag Bhatia

As suspected, this ended up being an XO/DTAG peering issue. Took a
long time to get sorted out, but thanks to any and all who assisted!