David Sotnick wrote:

I'm seeing *consistent* 46.1% packet loss between Comcast Res/Bus services in Northern CA and Pixar (Level 3 customer) also in Northern CA. I have ticket open with Level (3) but the problem appears to be on Comcast's network.

5/12 = 41.6% Someone's got a 12-way LAG / ECMP path with either 5 links broken or else with a hashing algorithm which is dumping your packets into one or more broken paths 5/12 of the time. Nick

Will get appropriate folks engaged. Thanks. -----Original Message----- From: NANOG <nanog-bounces@nanog.org> on behalf of David Sotnick <sotnickd-nanog@ddv.com> Date: Monday, May 23, 2016 at 1:59 PM To: "nanog@nanog.org" <nanog@nanog.org> Subject: Need Comcast IPv6 routing assistance please Hello NANOG, Could someone from Comcast IPv6 routing team please contact me directly? I am both a business and residential comcast customer and my employer is a Level(3) HSIP customer at multiple sites. I'm seeing *consistent* 46.1% packet loss between Comcast Res/Bus services in Northern CA and Pixar (Level 3 customer) also in Northern CA. I have ticket open with Level (3) but the problem appears to be on Comcast's network. Sample trace: My traceroute [v0.85] ipv6testhost.ddv.com (::) Mon May 23 10:56:05 2016 Keys: Help Display mode Restart statistics Order of fields quit Packets Pings Host Loss% Snt Last Avg Best Wrst StDev 1. 2601:647:280:23::1 0.0% 464 0.6 0.4 0.3 8.7 0.4 2. 2001:558:4000:3d::1 0.2% 463 13.0 10.3 8.2 27.4 2.1 3. te-0-7-0-5-sur03.sanrafael.ca.sfba.comcast.net 10.2% 463 9.6 10.7 8.5 34.8 2.4 4. be-207-rar01.rohnertpr.ca.sfba.comcast.net 44.7% 463 10.6 11.7 9.4 25.9 2.1 5. he-0-18-0-0-ar01.santaclara.ca.sfba.comcast.net 51.6% 463 15.2 14.1 12.0 26.2 1.9 6. 2001:1900:4:3::439 46.0% 463 13.3 14.4 11.8 50.2 3.6 7. vl-80.edge1.SanJose1.Level3.net 44.9% 463 12.1 13.9 11.7 28.5 2.3 8. vl-4045.edge5.LosAngeles.Level3.net 45.4% 463 21.2 21.5 19.2 39.4 2.6 9. vl-4044.bar1.LasVegas1.Level3.net 46.4% 463 24.9 27.7 24.4 88.3 6.8 10. vl-5.car1.LasVegas1.Level3.net 46.2% 463 104.3 46.3 24.5 318.2 48.0 11. PIXAR-ANIMA.car1.LasVegas1.Level3.net 44.9% 463 27.6 27.4 25.0 37.7 2.1 12. 2620:79:0:b04d::249 45.1% 463 46.4 48.9 46.0 114.2 4.9 And pings back from Pixar: Type escape sequence to abort.Sending 500, 100-byte ICMP Echos to 2601:647:0:1900:242:DEA1:FEC9:FFAE, timeout is 2 seconds: Packet sent with a source address of 2620:79:0:B04D::249%internet.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!..!.!!!!!!!!!!!!..!!!!!!!!!...!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!..!!!!!!!!!!!!!!!...!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!..!!!!!.!!!!!!!!!!!!!!!!!!!!!!!..!.!!!!!!!!!!!!!!!!!!..!!!!!!!!!!!!!!!!!!!!...!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!..!!.!!!!..!!!!!!!!!...!!!!!!!!!!!!!....!!!!!!!!..!!!!!!!!!....!!!!!..!!!!!!!!!!!!!!!!!!!!!!...!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!Success rate is 90 percent (452/500), round-trip min/avg/max = 12/30/68 ms Any help really appreciated as you can imagine how painful remote access for our employees with Comcast connections into Pixar over IPv6 is right now. Many Thanks, David