Re: Comcast - Stuck route in Chicago directing MN traffic via Denver

[Eric Spaeth <eric () spaethco com>]

Thanks for the folks who looked at this -- things are looking better 
this morning:

traceroute to 76.113.128.1 (76.113.128.1), 30 hops max, 40 byte packets
1  69.65.40.62 (69.65.40.62)  0.858 ms  0.840 ms  0.838 ms
2  so2-0-0-0.er1.Chi1.Servernap.net (69.39.239.169)  1.876 ms  1.878 
ms  1.875 ms
3  ge-6-20.car1.Chicago1.Level3.net (4.79.65.49)  1.854 ms  1.858 ms  
1.855 ms
4  ae-2-54.edge1.Chicago2.Level3.net (4.68.101.115)  60.047 ms  60.068 
ms  60.067 ms
5  COMCAST-IP.edge1.Chicago2.Level3.net (4.71.248.26)  3.045 ms  3.051 
ms  3.049 ms
6  te-0-2-0-5-ar03.roseville.mn.minn.comcast.net (68.87.174.73)  12.172 
ms  12.267 ms  12.250 ms
7  te-2-1-ur01.sims.mn.minn.comcast.net (68.87.174.74)  11.717 ms * *
8  te-8-3-ur02.sims.mn.minn.comcast.net (68.87.174.78)  11.940 ms * *
9  te-2-1-ur01.newport.mn.minn.comcast.net (68.87.174.82)  12.224 ms * *
10  c-76-113-128-1.hsd1.mn.comcast.net (76.113.128.1)  12.203 ms  12.203 
ms  12.045 ms

-Eric

Eric Spaeth wrote:
> For the last couple weeks there has been a route stuck in the Chicago 
> wan/core that is directing some Minnesota-bound traffic through 
> Denver, even though Chicago and the Roseville, MN aggregation remain 
> up and directly connected.  This has the dual benefit of unnecessarily 
> increasing the load on Comcast's internal backbone as well as 
> increasing latency for Minnesota subscribers connecting to "east of 
> the Mississippi" destinations by ~20ms.
>
> I'm hoping Comcast engineers read this list, or someone in the carrier 
> community can help poke one of their Comcast contacts to help get this 
> resolved.
>
> Thanks in advance!
> "Wedged" route -  76.113.128.0/17
> Correct route - 69.180.128.0/18
>
> Example trace from Chicago source to 76.113.128.0/17:
> =========================================
> traceroute to 76.113.128.1 (76.113.128.1), 30 hops max, 40 byte packets
> 1  69.65.40.62 (69.65.40.62)  0.542 ms  0.511 ms  0.508 ms
> 2  so2-0-0-0.er1.Chi1.Servernap.net (69.39.239.169)  1.632 ms  1.642 
> ms  2.121 ms
> 3  ge-6-20.car1.Chicago1.Level3.net (4.79.65.49)  1.605 ms  1.608 ms  
> 1.619 ms
> 4  ae-2-54.edge1.Chicago2.Level3.net (4.68.101.115)  1.604 ms  1.602 
> ms  1.600 ms
> 5  COMCAST-IP.edge1.Chicago2.Level3.net (4.71.248.26)  2.735 ms  2.741 
> ms  2.739 ms
> 6  pos-0-8-0-0-cr01.denver.co.ibone.comcast.net (68.86.85.114)  27.284 
> ms  27.398 ms  27.387 ms
> 7  te-9-4-ar02.roseville.mn.minn.comcast.net (68.86.91.154)  44.177 ms 
> * *
> 8  te-0-2-0-5-ar03.roseville.mn.minn.comcast.net (68.87.174.73)  
> 28.352 ms  28.352 ms  28.349 ms
> 9  te-2-1-ur01.sims.mn.minn.comcast.net (68.87.174.74)  28.826 ms * *
> 10  te-8-3-ur02.sims.mn.minn.comcast.net (68.87.174.78)  28.959 ms * *
> 11  te-2-1-ur01.newport.mn.minn.comcast.net (68.87.174.82)  29.267 ms 
> * te-2-1-ur01.newport.mn.minn.comcast.net (68.87.174.82)  28.700 ms
> 12  c-76-113-128-1.hsd1.mn.comcast.net (76.113.128.1)  28.638 ms  
> 28.673 ms  28.667 ms
> =========================================
>
> Example trace from Chicago source to working route 69.180.128.0/18
> =========================================
> traceroute to 69.180.130.1 (69.180.130.1), 30 hops max, 40 byte packets
> 1  69.65.40.62 (69.65.40.62)  0.482 ms  0.450 ms  0.446 ms
> 2  so2-0-0-0.er1.Chi1.Servernap.net (69.39.239.169)  1.595 ms  2.082 
> ms  2.082 ms
> 3  ge-6-20.car1.Chicago1.Level3.net (4.79.65.49)  1.568 ms  1.569 ms  
> 1.579 ms
> 4  ae-2-52.edge1.Chicago2.Level3.net (4.68.101.51)  1.562 ms  1.563 
> ms  1.560 ms
> 5  COMCAST-IP.edge1.Chicago2.Level3.net (4.71.248.22)  2.708 ms  2.713 
> ms  2.711 ms
> 6  te-0-1-0-7-ar03.roseville.mn.minn.comcast.net (68.87.174.21)  
> 13.144 ms  11.919 ms  11.877 ms
> 7  68.87.174.22 (68.87.174.22)  11.824 ms * *
> 8  te-8-3-ur02.brooklynpark.mn.minn.comcast.net (68.87.174.26)  12.333 
> ms * *
> 9  te-2-1-ur01.newhope.mn.minn.comcast.net (68.87.174.30)  12.012 ms * *
> 10  c-3-0-ubr02.newhope.mn.minn.comcast.net (69.180.130.1)  11.963 ms  
> 12.018 ms  11.973 ms
> =========================================
>
> -Eric