Web lists-archives.com

Re: intermittent name resolution failures




On Fri, Dec 28, 2018 at 3:51 AM <tomas@xxxxxxxxxx> wrote:
>
> Whenever your DNS fails try a "traceroute 8.8.8.8". Compare its results
> to what you get when you do it at times where your DNS works. Perhaps
> this sheds some light on it.

That is tough to capture because the problem is intermittent. When I
retry it seems to come back and vice versa. Instead I ran the
traceroute command 10 times and stored the output in trial_1.txt,
trial_2.txt, ... trial_10.txt in
http://kamaraju.xyz/tmp/network_issues/

Command used:
$ for i in `seq 1 10`; do traceroute 8.8.8.8 > trial_$i.txt; done

I see a lot of differences between trial_6.txt and trial_4.txt. Does
that mean anything or is this variation expected?

$ cat trial_6.txt
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  * * *
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * be3295.ccr31.jfk05.atlas.cogentco.com (154.54.80.2)  2.131 ms
be3294.ccr31.jfk05.atlas.cogentco.com (154.54.47.218)  2.078 ms
 7  level3.dfw03.atlas.cogentco.com (154.54.12.18)  1.905 ms  1.906 ms  2.038 ms
 8  if-ae-12-2.tcore1.n75-new-york.as6453.net (66.110.96.5)  2.274 ms
2.271 ms if-ae-12-4.tcore1.n75-new-york.as6453.net (66.110.96.59)
2.257 ms
 9  72.14.195.232 (72.14.195.232)  3.073 ms  3.074 ms *
10  * * *
11  * * *
12  * 108.170.235.183 (108.170.235.183)  2.605 ms 108.170.238.203
(108.170.238.203)  2.794 ms
13  google-public-dns-a.google.com (8.8.8.8)  2.182 ms  2.084 ms  2.044 ms

$ cat trial_4.txt
traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  38.76.11.1 (38.76.11.1)  0.416 ms  0.359 ms  0.412 ms
 2  gi0-2-0-6.rcr51.ewr04.atlas.cogentco.com (38.122.117.97)  1.213 ms
 1.197 ms  1.208 ms
 3  be3657.rcr21.ewr03.atlas.cogentco.com (154.24.33.169)  1.620 ms
1.514 ms  1.584 ms
 4  be2601.rcr24.jfk01.atlas.cogentco.com (154.54.40.49)  2.044 ms * *
 5  * * *
 6  * be3294.ccr31.jfk05.atlas.cogentco.com (154.54.47.218)  2.205 ms
be3295.ccr31.jfk05.atlas.cogentco.com (154.54.80.2)  2.085 ms
 7  level3.dfw03.atlas.cogentco.com (154.54.12.18)  1.674 ms  1.657 ms  1.745 ms
 8  if-ae-12-2.tcore1.n75-new-york.as6453.net (66.110.96.5)  2.147 ms
2.232 ms if-ae-12-4.tcore1.n75-new-york.as6453.net (66.110.96.59)
2.181 ms
 9  72.14.195.232 (72.14.195.232)  2.772 ms  2.766 ms  2.756 ms
10  * * *
11  * * 72.14.234.64 (72.14.234.64)  4.559 ms
12  209.85.243.193 (209.85.243.193)  2.346 ms 108.170.235.181
(108.170.235.181)  2.933 ms 74.125.37.97 (74.125.37.97)  2.650 ms
13  google-public-dns-a.google.com (8.8.8.8)  2.204 ms  2.200 ms  2.231 ms

thanks
raju
-- 
Kamaraju S Kusumanchi | http://raju.shoutwiki.com/wiki/Blog