Level3 -> AS3549 US IPv6 Routing

Adam Furman afurman at amf.net
Fri Oct 4 21:20:25 UTC 2013


I have noticed for the last couple of weeks that Level3 is routing IPV6
traffic to Global Crossing AS via Seattle.  Seeing it from multiple
connection's we have in the US plus Level3 Looking Glass also shows the
routes learned in Seattle from DC. I can't see them only peering in
Seattle from US location's, Europe is different seems to be routing
correctly from what I see on the looking glass.

Route results for 2001:450::/32 from Washington, DC

BGP routing table entry for 2001:450::/32
Paths: (2 available, best #1)
  3549, (aggregated by 3549 err41.sea1.gblx.mgmt)
  AS-path translation: { GBLX }
    2001:1900::3:91 (metric 7502)
      Origin IGP, localpref 100, valid, internal, atomic-aggregate, best
      Community: 3549:5001 3549:30840
      Originator: edge1.Seattle3
  3549, (aggregated by 3549 err41.sea1.gblx.mgmt)
  AS-path translation: { GBLX }
    2001:1900::3:91 (metric 7502)
      Origin IGP, localpref 100, valid, internal, atomic-aggregate
      Community: 3549:5001 3549:30840
      Originator: edge1.Seattle3

Route results for 2001:450::/32 from Frankfurt, Germany
BGP routing table entry for 2001:450::/32
Paths: (2 available, best #1)
  3549, (aggregated by 3549 err41.fra4.gblx.mgmt)
  AS-path translation: { GBLX }
    2001:1900:2::3:8 (metric 40)
      Origin IGP, metric 100000, localpref 86, valid, internal,
atomic-aggregate, best
      Community: Europe  Lclprf_86 Germany IPv6-valid Level3_Peer
Community_ERROR Frankfurt
      Originator: edge4.Frankfurt1
  3549, (aggregated by 3549 err41.fra4.gblx.mgmt)
  AS-path translation: { GBLX }
    2001:1900:2::3:8 (metric 40)
      Origin IGP, metric 100000, localpref 86, valid, internal,
atomic-aggregate
      Community: Europe  Lclprf_86 Germany IPv6-valid Level3_Peer
Community_ERROR Frankfurt
      Originator: edge4.Frankfurt1



Traceroute from one of my connections in DC.  Doesn't matter what I source
the route from.  I have also seen this to customers behind AS3549 too.

 4. vl-4081.edge2.washington1.level3  0.0%     7    1.6   1.6   1.6   1.6
 0.0
 5. vl-4061.car1.newyork2.level3.net  0.0%     7    6.9   7.5   6.9  10.6
 1.4
 6. vl-4081.car2.newyork2.level3.net  0.0%     7    7.0  41.0   7.0 158.2
61.0
 7. vl-4061.car1.chicago1.level3.net  0.0%     7   27.7  27.5  27.4  27.7
 0.1
 8. vl-4040.edge1.chicago2.level3.ne  0.0%     7   27.7  30.0  27.6  44.3
 6.3
 9. vl-4042.edge6.denver1.level3.net  0.0%     7   51.9  51.9  51.8  52.0
 0.1
10. vl-4060.car2.seattle1.level3.net  0.0%     6  186.2 119.0  78.5 186.2
51.6
11. 2001:1900:1b:1::9                 0.0%     6   78.4  78.4  78.3  78.6
 0.1
12. 2001:450:2008:100::135            0.0%     6   86.4  87.2  86.4  90.0
 1.4
13. 2001:450:2002:288::2              0.0%     6   85.2  85.3  85.1  85.5
 0.1


If I route this traffic via Telia it goes direct to Global Crossing's with
a much lower latency.  Has anyone else seen this issue with Level3?

Thanks,
Adam





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