Re: buildfarm server suddenly not talking to old SSL stacks?

On 07/17/2018 09:22 PM, Tom Lane wrote:
> Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc> writes:
>> On 07/17/2018 08:58 PM, Tom Lane wrote:
>>> Now I'm completely confused. This is going through a different ISP
>>> and significantly different network path to reach rackspace, but
>>> that shouldn't have anything to do with it? *Something* is darn
>>> weird here.
>
>> given it does not yet seem to have been discussed in this thread - ipv4
>> vs ipv6 (either direct or indirect through CGN or similiar technologies)?
>
> Good thought, but at least at my end it's all IPv4, and traceroute
> doesn't suggest there's anything else between. The RHEL6 box sees
> this traceroute:
>
> $ traceroute buildfarm.postgresql.org
> traceroute to buildfarm.postgresql.org (174.143.35.217), 30 hops max, 60 byte packets
> 1 router1.sss.pgh.pa.us (192.168.168.5) 3.705 ms 4.465 ms 5.528 ms
> 2 192.168.252.29 (192.168.252.29) 18.278 ms 19.285 ms 20.719 ms
> 3 gw.aspStation.net (66.207.128.1) 22.197 ms 23.351 ms 24.578 ms
> 4 144.232.10.211 (144.232.10.211) 25.990 ms 27.226 ms 28.582 ms
> 5 144.232.10.210 (144.232.10.210) 29.884 ms 31.063 ms 33.532 ms
> 6 144.232.14.7 (144.232.14.7) 32.215 ms 46.337 ms 44.983 ms
> 7 144.232.15.174 (144.232.15.174) 46.679 ms 144.232.14.10 (144.232.14.10) 34.810 ms 35.586 ms
> 8 144.232.15.121 (144.232.15.121) 35.414 ms 34.871 ms 35.634 ms
> 9 sl-above1-722053-0.sprintlink.net (144.228.205.158) 35.691 ms 35.101 ms 35.580 ms
> 10 ae1.cr2.dca2.us.zip.zayo.com (64.125.20.121) 35.510 ms 34.947 ms 35.528 ms
> 11 ae27.cs2.dca2.us.eth.zayo.com (64.125.30.248) 83.111 ms 82.605 ms 87.833 ms
> 12 ae4.cs2.lga5.us.eth.zayo.com (64.125.29.30) 98.348 ms 97.706 ms 97.689 ms
> 13 ae3.cs2.ord2.us.eth.zayo.com (64.125.29.213) 85.612 ms 85.198 ms 85.710 ms
> 14 ae5.cs2.den5.us.eth.zayo.com (64.125.29.216) 85.700 ms 85.143 ms 85.800 ms
> 15 ae7.cs2.den5.us.eth.zayo.com (64.125.31.237) 91.259 ms 90.791 ms 91.310 ms
> 16 ae28.er1.dfw2.us.zip.zayo.com (64.125.26.15) 85.946 ms 69.331 ms 69.892 ms
> 17 128.177.70.86.IPYX-076520-900-ZYO.zip.zayo.com (128.177.70.86) 69.761 ms 87.568 ms 88.741 ms
> 18 * * *
> 19 74.205.108.121 (74.205.108.121) 85.957 ms be42.coreb.dfw1.rackspace.net (74.205.108.125) 85.334 ms be41.corea.dfw1.rackspace.net (74.205.108.113) 85.820 ms
> 20 core5-coreb.dfw1.rackspace.net (74.205.108.27) 76.332 ms po1.CoreA.core6.dfw1.rackspace.net (72.32.111.13) 84.456 ms po2.CoreB.core6.dfw1.rackspace.net (72.32.111.15) 77.344 ms
> 21 core5-aggr313a.dfw1.rackspace.net (67.192.56.63) 83.224 ms 82.713 ms 71.320 ms
> 22 * * *
> 23 * * *
> 24 * * *
> 25 * * *
> 26 * * *
> 27 * * *
> 28 * * *
> 29 * * *
> 30 * * *
>
> while the buildfarm critters are going through verizon:
>
> $ traceroute buildfarm.postgresql.org
> traceroute to buildfarm.postgresql.org (174.143.35.217), 64 hops max, 40 byte packets
> 1 router2 (192.168.168.2) 5.031 ms 4.108 ms 4.195 ms
> 2 * * *
> 3 b3309.pitbpa-lcr-22.verizon-gni.net (130.81.28.70) 133.770 ms 8.250 ms 8.069 ms
> 4 * * *
> 5 * * *
> 6 0.et-7-3-0.br1.iad8.alter.net (140.222.239.83) 16.920 ms 0.et-5-1-5.br1.iad8.alter.net (140.222.0.65) 16.547 ms 14.896 ms
> 7 xe-2-1-0.er2.iad10.us.zip.zayo.com (64.125.13.173) 15.706 ms 14.482 ms 14.481 ms
> 8 ae1.cr2.dca2.us.zip.zayo.com (64.125.20.121) 15.731 ms 17.841 ms 17.265 ms
> 9 ae27.cs2.dca2.us.eth.zayo.com (64.125.30.248) 68.536 ms 68.973 ms 67.971 ms
> 10 ae4.cs2.lga5.us.eth.zayo.com (64.125.29.30) 67.021 ms 68.627 ms 67.130 ms
> 11 ae3.cs2.ord2.us.eth.zayo.com (64.125.29.213) 67.277 ms 67.727 ms 68.079 ms
> 12 ae5.cs2.den5.us.eth.zayo.com (64.125.29.216) 66.520 ms 69.493 ms 73.931 ms
> 13 ae7.cs2.den5.us.eth.zayo.com (64.125.31.237) 193.146 ms 66.854 ms 67.034 ms
> 14 ae28.er1.dfw2.us.zip.zayo.com (64.125.26.15) 149.815 ms 67.910 ms 70.480 ms
> 15 128.177.70.86.ipyx-076520-900-zyo.zip.zayo.com (128.177.70.86) 68.615 ms 78.398 ms 70.127 ms
> 16 * * *
> 17 be41.coreb.dfw1.rackspace.net (74.205.108.117) 73.871 ms 74.205.108.121 (74.205.108.121) 67.374 ms 70.223 ms
> 18 core5-corea.dfw1.rackspace.net (74.205.108.11) 72.848 ms po1.corea.core6.dfw1.rackspace.net (72.32.111.13) 69.176 ms core5-corea.dfw1.rackspace.net (74.205.108.11) 70.037 ms
> 19 po2.core6.aggr313a.rackspace.net (72.32.111.211) 203.537 ms 70.130 ms core5-aggr313a.dfw1.rackspace.net (67.192.56.63) 70.854 ms
> 20 * * *
> 21 * * *
> 22 * * *
> 23 * * *
> 24 * * *
> 25 * * *
> 26 * * *
> 27 * * *
> 28 * * *
> 29 * * *
> 30 * * *
>
> Also, if the issue is somewhere in between, that fails to explain why
> "curl" works but not perl.

not sure that proofs that v4 vs v6 is out entirely, there could be other
factors involved (like your isp mapping v4 to v6 on the router(!) maybe
combined with dns64/dns46 related tricks).
It should still be possible to figure out where exactly the "network
unreachable" comes from - whether it is something the local tcp/ip stack
generates or something that comes in as an icmp-error from remote using
tcpdump or similiar.

Stefan