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  • host resolution fails for certain hosts

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    I have an odd problem with djbdns. A couple of common hosts (and I
    suspect others) don't resolve but nearly everything else works fine and
    has for years. This problem has existed for years but I never took the
    time to fix it. I want to fix it!
    e.g.
    These don't work:
    # host www.edmunds.com
    ;; connection timed out; no servers could be reached
    # host www.infiniti.com
    ;; connection timed out; no servers could be reached
    Yet most work:
    # host news.bbc.co.uk
    news.bbc.co.uk. is an alias for newswww.bbc.net.uk.
    newswww.bbc.net.uk. has address 212.58.240.143
    # host www.boston.com
    www.boston.com. has address 66.151.183.21
    www.boston.com. has address 66.151.183.31
    Here are the RT servers:
    # cat dnscache/root/servers/@
    198.41.0.4
    192.228.79.201
    192.33.4.12
    128.8.10.90
    192.203.230.10
    192.5.5.241
    192.112.36.4
    128.63.2.53
    192.36.148.17
    192.58.128.30
    193.0.14.129
    198.32.64.12
    202.12.27.33
    # dig www.edmunds.com @216.255.129.249
    ; <<>DiG 9.1.3 <<>www.edmunds.com @216.255.129.249
    ;; global options: printcmd
    ;; Got answer:
    ;; HEADER<<- opcode: QUERY, status: REFUSED, id: 41115
    ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHRITY: 0, ADDITINAL: 0
    ;; QUESTIN SECTIN:
    ;www.edmunds.com. IN A
    ;; Query time: 28 msec
    ;; SERVER: 216.255.129.249#53(216.255.129.249)
    ;; WHEN: Sat Jan 14 23:55:33 2006
    ;; MSG SIZE rcvd: 33
    What could be the problem? How do I go about diagnosing this?

  • No.1 | | 1574 bytes | |

    Robert La Ferla wrote:
    # host www.edmunds.com
    ;; connection timed out; no servers could be reached
    # host www.infiniti.com
    ;; connection timed out; no servers could be reached

    If you are having problems with djbdns, why are you using a BIND tool that even
    the BIND people think is hopelessly broken? You should do something like this:

    $ dnsqr a www.edmunds.com
    1 www.edmunds.com:
    136 bytes, 1+4+0+0 records, response, noerror
    query: 1 www.edmunds.com
    answer: www.edmunds.com 300 CNAME www.edmunds.com.edgesuite.net
    answer: www.edmunds.com.edgesuite.net 21600 CNAME a332.g.akamai.net
    answer: a332.g.akamai.net 20 A 66.92.159.70
    answer: a332.g.akamai.net 20 A 66.92.159.72

    $ dnsqr a www.infiniti.com
    1 www.infiniti.com:
    141 bytes, 1+4+0+0 records, response, noerror
    query: 1 www.infiniti.com
    answer: www.infiniti.com 300 CNAME
    answer: 21600 CNAME a175.g.akamai.net
    answer: a175.g.akamai.net 20 A 66.92.159.72
    answer: a175.g.akamai.net 20 A 66.92.159.70

    NTE: both those addresses are serviced by Akamai (a load-balancing service) so
    you are likely to get very different answers.

    # dig www.edmunds.com @216.255.129.249

    The way to do that using the djbdns tools is:

    $ DNSCACHEIP=216.255.129.249 dnsqr a www.edmunds.com

    However, why are you trying to resolve that hostname with one of the Digex
    nameservers? Are you are Digex client? It appears they have their nameserver
    set up to refuse queries from random hosts (I cannot use it, for example).

    John

  • No.2 | | 1824 bytes | |

    Sun Jan 15, 2006 at 09:40:40 -0500, John Peacock wrote:
    >Robert La Ferla wrote:
    ># host www.edmunds.com
    >;; connection timed out; no servers could be reached
    ># host www.infiniti.com
    >;; connection timed out; no servers could be reached
    >
    >If you are having problems with djbdns, why are you using a BIND tool that even
    >the BIND people think is hopelessly broken? You should do something like this:

    *snore*


    >NTE: both those addresses are serviced by Akamai (a load-balancing service) so
    >you are likely to get very different answers.
    >
    ># dig www.edmunds.com @216.255.129.249
    >
    >The way to do that using the djbdns tools is:
    >
    >$ DNSCACHEIP=216.255.129.249 dnsqr a www.edmunds.com
    >
    >However, why are you trying to resolve that hostname with one of the Digex
    >nameservers? Are you are Digex client? It appears they have their nameserver
    >set up to refuse queries from random hosts (I cannot use it, for example).

    Perhaps because of:

    edmunds.com. 172800 IN NS mia01.digex.com.

    The digex.com name servers refuse queries with the recursive flag set-
    behaviour that should not be surprising to people who use djbdns.

    The real problem here is that Dan refuses to fix code that breaks on a
    DNS configuration (akamai's) that, while not illegal, is substantially
    more complex in practice than was anticipated when he coded dnscache.
    Google for akamai + dnscache.

    To paraphrase

    Akamai: It works for MaraDNS. It works for PowerDNS. It works for
    Nominum CNS. It works for Microsoft DNS. It works for hundreds of
    millions of BIND users. It just doesn't work for djb.

  • No.3 | | 1177 bytes | |

    Sun, 15 Jan 2006 08:46:35 -0500
    Robert La Ferla <robert (AT) laferla (DOT) netwrote:

    I have an odd problem with djbdns. A couple of common hosts (and I
    suspect others) don't resolve but nearly everything else works fine
    and has for years. This problem has existed for years but I never
    took the time to fix it. I want to fix it!

    e.g.

    These don't work:

    They work here (using dnscache).

    # host www.edmunds.com
    ;; connection timed out; no servers could be reached

    blinky:/home/sae$ dnsip www.edmunds.com
    193.108.94.23 193.108.94.6

    # host www.infiniti.com
    ;; connection timed out; no servers could be reached

    blinky:/home/sae$ dnsip www.infiniti.com
    193.108.94.15 193.108.94.17

    # dig www.edmunds.com @216.255.129.249

    blinky:/home/sae$ dnsq a www.edmunds.com 216.255.129.249
    1 www.edmunds.com:
    76 bytes, 1+1+0+0 records, response, authoritative, noerror
    query: 1 www.edmunds.com
    answer: www.edmunds.com 300 CNAME www.edmunds.com.edgesuite.net

    What could be the problem? How do I go about diagnosing this?

    You could have a look at the dnscache logs?

  • No.4 | | 212 bytes | |

    Sun, 15 Jan 2006 18:16:33 +0100
    Stefaan A Eeckels <Stefaan.Eeckels (AT) ecc (DOT) luwrote:
    Something with the Disposition-Notification-To header.
    Apologies, I used the wrong account to reply.

  • No.5 | | 364 bytes | |

    Mon Jan 16, 2006 at 15:12:09 -0500, Charlie Brady wrote:
    >
    >We should remember that people deploy dnscache not to verify DNS data at
    >remote servers, but to resolve names.
    >

    Hear, hear.

    ( It sounds even better if you imagine it in the voice of Jon Postel,
    reading aloud from RFC 793. )

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