[Pool] Monitoring says my server is unreachable

Kasper Pedersen timekeepers at kasperkp.dk
Wed Feb 26 17:53:51 UTC 2014


On 02/26/2014 01:15 PM, Marek Podmaka wrote:

> Any ideas how to troubleshoot further? Can you test from other
> coutries and report if can't get time from me? (monlist is blocked,
> but for example ntpdate -q 92.240.244.202 should work). So it seems
> like it is blocked somewhere in the transit.
> 

traceroute lets you specify source and destination ports
(apologies for long lines, but it is rather unreadable otherwise)

>From Atlanta, I see the problem.

On the first hop into interoute, packets with source 
port 123 get dropped.
(Remember that the reply packets are icmp messages, so 
this is only shows filters in one direction, not both)

root at us:~# traceroute -p 123 --sport=123 92.240.244.202
traceroute to 92.240.244.202 (92.240.244.202), 30 hops max, 60 byte packets
 1  74-114-251-162-static.reverse.queryfoundry.net (162.251.114.74)  0.103 ms  0.108 ms  0.035 ms
 2  41-12-68-38-static.reverse.queryfoundry.net (38.68.12.41)  1.108 ms  1.378 ms  0.877 ms
 3  33-13-68-38-static.reverse.queryfoundry.net (38.68.13.33)  0.912 ms  0.867 ms  0.615 ms
 4  core-0.clgx.dfw.queryfoundry.net (38.68.13.1)  0.366 ms  0.299 ms  0.198 ms
 5  ge5-13.br02.dal01.pccwbtn.net (63.218.23.65)  0.243 ms  0.237 ms  0.278 ms
 6  tinet.tenge13-4.br03.ash01.pccwbtn.net (63.218.92.90)  34.604 ms  38.679 ms  35.076 ms
 7  xe-3-0-0.par72.ip4.tinet.net (141.136.109.90)  110.730 ms xe-3-2-0.par72.ip4.tinet.net (89.149.187.14)  114.011 ms xe-9-3-0.par72.ip4.tinet.net (141.136.111.161)  113.155 ms
 8  * *^C



packets with a different source port do not get dropped.

root at us:~# traceroute -p 123 --sport=124 92.240.244.202
traceroute to 92.240.244.202 (92.240.244.202), 30 hops max, 60 byte packets
 1  74-114-251-162-static.reverse.queryfoundry.net (162.251.114.74)  0.078 ms  0.071 ms  0.037 ms
 2  41-12-68-38-static.reverse.queryfoundry.net (38.68.12.41)  2.096 ms  1.119 ms  1.520 ms
 3  33-13-68-38-static.reverse.queryfoundry.net (38.68.13.33)  1.098 ms  0.982 ms  0.751 ms
 4  core-0.clgx.dfw.queryfoundry.net (38.68.13.1)  0.379 ms  0.369 ms  0.229 ms
 5  ge5-13.br02.dal01.pccwbtn.net (63.218.23.65)  0.313 ms  0.261 ms  0.258 ms
 6  tinet.tenge13-4.br03.ash01.pccwbtn.net (63.218.92.90)  52.927 ms  51.432 ms  51.208 ms
 7  xe-8-3-0.par72.ip4.tinet.net (89.149.185.37)  127.578 ms  138.778 ms xe-3-2-0.par72.ip4.tinet.net (89.149.187.14)  133.554 ms
 8  interoute-gw.ip4.tinet.net (77.67.75.238)  141.171 ms  139.420 ms  169.158 ms
 9  ae0-0.par-gar-score-2-re0.interoute.net (212.23.42.26)  158.395 ms  155.614 ms  158.323 ms
10  ae1-0.fra-006-score-2-re1.interoute.net (212.23.42.30)  149.717 ms  151.316 ms  150.208 ms
11  ae0-0.fra-006-score-1-re0.interoute.net (84.233.207.93)  150.646 ms  148.532 ms  209.359 ms
12  ae1-0.vie-per-score-1-re0.interoute.net (212.23.43.25)  156.621 ms  157.447 ms  159.537 ms
13  ae0-0.vie-per-score-2-re0.interoute.net (212.23.43.50)  151.840 ms  148.812 ms  152.683 ms
14  ae1-0.bts-001-score-1-re0.interoute.net (84.233.147.13)  151.384 ms  149.281 ms  150.220 ms
15  89.202.153.150 (89.202.153.150)  154.448 ms  152.148 ms  150.778 ms
16  121.224.240.92.in-addr.arpa.lightstorm.sk (92.240.224.121)  159.447 ms  157.332 ms  159.591 ms
17  118.224.240.92.in-addr.arpa.lightstorm.sk (92.240.224.118)  154.009 ms  151.081 ms  151.731 ms
18  kenny.oneemedia.com (92.240.244.202)  159.507 ms  159.393 ms  162.500 ms


>From Amsterdam, the packets can get to the server, but the 
reply can not get back to snelis (ntpdate -q does not receive a reply)

[root at nl ~]# traceroute -p 123 --sport=123 92.240.244.202
traceroute to 92.240.244.202 (92.240.244.202), 30 hops max, 60 byte packets
 1  snelis.com (89.207.130.1)  0.282 ms  5.471 ms  1.131 ms
 2  80ge.cr1-br2-br3.smartdc.rtd.i3d.net (188.122.95.81)  0.365 ms  8.350 ms  4.632 ms
 3  20ge.fr0-cr1.inxn-1.fra.i3d.net (109.200.218.6)  11.425 ms 30ge.ar0-cr1.nikhef.ams.i3d.net (109.200.218.85)  2.168 ms 20ge.fr0-cr1.inxn-1.fra.i3d.net (109.200.218.6)  11.941 ms
 4  ams-001.interoute.net (195.69.144.81)  2.247 ms  2.592 ms  2.270 ms
 5  ae0-0.ams-koo-score-2-re0.interoute.net (84.233.190.2)  25.121 ms  32.497 ms  26.277 ms
 6  ae1-0.fra-006-score-1-re0.interoute.net (84.233.190.50)  46.579 ms  25.528 ms ae1-0.vie-per-score-1-re0.interoute.net (212.23.43.25)  20.907 ms
 7  ae0-0.vie-per-score-2-re0.interoute.net (212.23.43.50)  20.215 ms  18.989 ms  20.241 ms
 8  ae0-0.vie-per-score-2-re0.interoute.net (212.23.43.50)  19.696 ms  40.397 ms  20.485 ms
 9  ae1-0.bts-001-score-1-re0.interoute.net (84.233.147.13)  21.583 ms 89.202.153.150 (89.202.153.150)  21.328 ms  22.508 ms
10  121.224.240.92.in-addr.arpa.lightstorm.sk (92.240.224.121)  20.989 ms  22.086 ms  21.969 ms
11  118.224.240.92.in-addr.arpa.lightstorm.sk (92.240.224.118)  20.672 ms  21.901 ms  20.630 ms
12  118.224.240.92.in-addr.arpa.lightstorm.sk (92.240.224.118)  21.355 ms  21.792 ms  21.405 ms
13  kenny.oneemedia.com (92.240.244.202)  21.823 ms  20.648 ms  21.854 ms
(but no reply to ntp, so there is filtering in the return path) 


Again Amsterdam, but coming out of i3d, we again hit interoute, 
and only for packets with source port 123:

root at vp:~# traceroute -p 123 --sport=123 92.240.244.202
traceroute to 92.240.244.202 (92.240.244.202), 30 hops max, 60 byte packets
 1  3.eur.p.year.server.at.lowendspirit.com (213.163.67.25)  0.191 ms  0.073 ms  0.037 ms
 2  80ge.cr0-br2-br3.smartdc.rtd.i3d.net (188.122.95.89)  2.605 ms  0.259 ms  0.239 ms
 3  30ge.ar0-cr0.nikhef.ams.i3d.net (109.200.218.74)  1.950 ms  2.278 ms  1.969 ms
 4  *^C

root at vp:~# traceroute -p 123 --sport=124 92.240.244.202
traceroute to 92.240.244.202 (92.240.244.202), 30 hops max, 60 byte packets
 1  3.eur.p.year.server.at.lowendspirit.com (213.163.67.25)  0.146 ms  0.079 ms  0.038 ms
 2  80ge.cr0-br2-br3.smartdc.rtd.i3d.net (188.122.95.89)  2.000 ms  6.163 ms  3.703 ms
 3  30ge.ar0-cr0.nikhef.ams.i3d.net (109.200.218.74)  2.419 ms  1.967 ms  2.571 ms
 4  fra-006-score-2.interoute.net (80.81.193.9)  7.977 ms 195.69.144.175 (195.69.144.175)  3.358 ms fra-006-score-2.interoute.net (80.81.193.9)  7.921 ms
 5  ae1-0.fra-006-score-1-re0.interoute.net (84.233.190.50)  21.693 ms  21.775 ms ae0-0.fra-006-score-1-re0.interoute.net (84.233.207.93)  20.837 ms
 6  ae1-0.vie-per-score-1-re0.interoute.net (212.23.43.25)  21.673 ms  20.733 ms ae1-0.fra-006-score-1-re0.interoute.net (84.233.190.50)  30.239 ms
 7  ae1-0.vie-per-score-1-re0.interoute.net (212.23.43.25)  45.776 ms  32.569 ms  21.810 ms
 8  ae1-0.bts-001-score-1-re0.interoute.net (84.233.147.13)  21.523 ms  20.547 ms  21.540 ms
 9  89.202.153.150 (89.202.153.150)  21.358 ms ae1-0.bts-001-score-1-re0.interoute.net (84.233.147.13)  21.270 ms  21.566 ms
10  89.202.153.150 (89.202.153.150)  22.130 ms  22.329 ms  22.052 ms
11  121.224.240.92.in-addr.arpa.lightstorm.sk (92.240.224.121)  22.092 ms  21.466 ms  21.790 ms^C

So Interoute.


/Kasper Pedersen


More information about the pool mailing list