IP resolving issue for LMS platform hosted within AWS

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5 comments

  • Avatar
    rotblitz (Edited )

    Does "returns the correct AWS servers and IP's a small fraction of the time, but most of the time it cant find the servers" mean that you're facing DNS query timeouts?  Or do you get NXDOMAIN responses?

    If you want, copy & paste the complete plain text output of the following diagnostic commands here when using OpenDNS or Umbrella, so that I can take a look.

    nslookup -type=txt debug.opendns.com.
    tracert 208.67.222.222
    tracert 208.67.220.220
    nslookup coresec.elearnnow.com.au.
    tracert coresec.elearnnow.com.au

    If you face timeouts with the above nslookup commands, use these instead:

    nslookup -timeout=8 -type=txt debug.opendns.com.
    nslookup -timeout=8 coresec.elearnnow.com.au.

     

  • Avatar
    iwilliams

    Hi.. thanks heaps..

    NSlookup output:

    nslookup -type=txt debug.opendns.com

    Server: 208.67.222.222

    Address: 208.67.222.222#53

     

    Non-authoritative answer:

    debug.opendns.com text = "server r2.mel1"

    debug.opendns.com text = "flags 20 0 70 180000000000000000007950800000000000000"

    debug.opendns.com text = "originid 0"

    debug.opendns.com text = "actype 0"

    debug.opendns.com text = "source 110.151.68.73:55140"

     

    Authoritative answers can be found from:

    Tracert for 208.67.222.222

    traceroute 208.67.222.222

    traceroute to 208.67.222.222 (208.67.222.222), 64 hops max, 52 byte packets

    1  10.0.0.138 (10.0.0.138)  2.929 ms  1.644 ms  2.586 ms

    2  * * *

    3  144.130.212.210 (144.130.212.210)  11.239 ms  10.395 ms  11.593 ms

    4  bundle-ether6.woo-core1.brisbane.telstra.net (203.50.11.138)  13.904 ms  12.278 ms  11.882 ms

    5  bundle-ether20.chw-core10.sydney.telstra.net (203.50.11.180)  20.533 ms  22.762 ms  21.873 ms

    6  bundle-ether8.exi-core10.melbourne.telstra.net (203.50.11.125)  34.888 ms  34.445 ms  35.170 ms

    7  bundle-ether1.lon-edge901.melbourne.telstra.net (203.50.11.108)  32.279 ms  33.351 ms  32.306 ms

    8  gtt2887670.lnk.telstra.net (110.145.221.42)  45.978 ms  34.223 ms  33.451 ms

    9  resolver1.opendns.com (208.67.222.222)  32.075 ms  33.724 ms  34.496 ms

     

    Tracert for 208.67.220.220

     

    traceroute 208.67.220.220

    traceroute to 208.67.220.220 (208.67.220.220), 64 hops max, 52 byte packets

    1  10.0.0.138 (10.0.0.138)  2.423 ms  1.359 ms  1.875 ms

    2  * * *

    3  144.130.212.210 (144.130.212.210)  14.274 ms  12.373 ms  10.051 ms

    4  bundle-ether6.woo-core1.brisbane.telstra.net (203.50.11.138)  11.513 ms  11.348 ms  12.295 ms

    5  bundle-ether20.chw-core10.sydney.telstra.net (203.50.11.180)  21.164 ms  22.932 ms  21.131 ms

    6  bundle-ether8.exi-core10.melbourne.telstra.net (203.50.11.125)  36.093 ms  33.187 ms  34.846 ms

    7  bundle-ether1.lon-edge901.melbourne.telstra.net (203.50.11.108)  34.621 ms  31.340 ms  32.516 ms

    8  gtt2887670.lnk.telstra.net (110.145.221.42)  33.943 ms  35.105 ms  34.276 ms

    9  resolver2.opendns.com (208.67.220.220)  32.494 ms  33.450 ms  33.277 ms

     

    NSlookup coresec

     

    nslookup coresec.elearnnow.com.au

    Server: 208.67.222.222

    Address: 208.67.222.222#53

     

    Non-authoritative answer:

    coresec.elearnnow.com.au canonical name = coresec.efrontlearning.com.

    coresec.efrontlearning.com canonical name = efront-ap-southeast-2-01.efrontlearning.com.

    Name: efront-ap-southeast-2-01.efrontlearning.com

    Address: 54.66.221.154

    Name: efront-ap-southeast-2-01.efrontlearning.com

    Address: 54.66.209.246

     

    Second attempt at nslookup for coresec.elearnnow.com.au (this is what my clients and I generally get most of the time performing an nslookup)

    nslookup -timeout=8 coresec.elearnnow.com.au

    Server: 208.67.222.222

    Address: 208.67.222.222#53

     

    ** server can't find coresec.elearnnow.com.au: SERVFAIL

    Traceroute for coresec.elearnnow.com.au

    first attempt:

    traceroute: unknown host coresec.elearnnow.com.au

    second attempt: Tracert is still going.. pasting what I have so far..

    traceroute coresec.elearnnow.com.au

    traceroute: Warning: coresec.elearnnow.com.au has multiple addresses; using 54.66.209.246

    traceroute to efront-ap-southeast-2-01.efrontlearning.com (54.66.209.246), 64 hops max, 52 byte packets

    1  10.0.0.138 (10.0.0.138)  8.405 ms  2.349 ms  1.610 ms

    2  * * *

    3  144.130.212.210 (144.130.212.210)  12.873 ms  9.939 ms  9.266 ms

    4  bundle-ether6.woo-core1.brisbane.telstra.net (203.50.11.138)  10.435 ms  10.962 ms  9.998 ms

    5  bundle-ether20.chw-core10.sydney.telstra.net (203.50.11.180)  23.122 ms  23.557 ms  20.916 ms

    6  bundle-ether1.chw-edge901.sydney.telstra.net (203.50.11.99)  24.024 ms  21.615 ms  20.004 ms

    7  ama1663432.lnk.telstra.net (165.228.50.194)  20.141 ms  23.176 ms  20.138 ms

    8  * * *

    9  * * *

    10  52.95.37.203 (52.95.37.203)  30.960 ms

        52.95.37.197 (52.95.37.197)  26.192 ms

        52.95.37.187 (52.95.37.187)  26.634 ms

    11  52.95.38.58 (52.95.38.58)  21.870 ms

        52.95.38.66 (52.95.38.66)  22.206 ms

        52.95.36.81 (52.95.36.81)  21.255 ms

    12  52.95.36.16 (52.95.36.16)  25.979 ms

        52.95.36.98 (52.95.36.98)  31.843 ms

        52.95.38.59 (52.95.38.59)  36.260 ms

    13  52.95.36.95 (52.95.36.95)  22.891 ms

        52.95.36.31 (52.95.36.31)  22.291 ms  25.152 ms

    14  52.95.38.19 (52.95.38.19)  29.500 ms

        52.95.38.154 (52.95.38.154)  24.235 ms

        52.95.38.160 (52.95.38.160)  21.622 ms

    15  * * *

    16  * * *

    17  * * *

    18  * * *

    19  * * *

    20  * * *

    21  * * *

    22  * * *

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    28  * * *

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    31  * * *

    32  * * *

    33  * * *

    34  * * *

    35  * * *

    36  * * *

    37  * * *

    38  * *

     

     

     

  • Avatar
    rotblitz

    It doesn't look like that your problems are related to OpenDNS/Umbrella or your ISP.  It rather seems that the DNS for CNAME coresec.elearnnow.com.au (with real name efront-ap-southeast-2-01.efrontlearning.com and another CNAME coresec.efrontlearning.com) is wrongly or incompletely configured.  This is also indicated by the SERVFAIL response you get.

    Work through this 3rd party results list of errors and warnings:
    https://mxtoolbox.com/domain/coresec.elearnnow.com.au/

  • Avatar
    iwilliams

    Thanks heaps - I am looking into it now..

    Strange how none of the other DNS servers I have seem to have any problems accessing the site.

    Really appreciate your advice.

  • Avatar
    rotblitz

    DNS servers do not access sites.  They just return responses to your DNS queries - if they can.  And they cannot due to misconfigured DNS configuration for this hostname.

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