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  • srv lookup in record

    From Marc Roos@M.Roos@f1-outsourcing.eu to bind-users on Sat Aug 22 00:26:02 2020
    From Newsgroup: comp.protocols.dns.bind


    Is it possible to use srv lookups, like eg cname. I do not want to
    create SRV record, I just want to 'get' the ip addresses, that I would
    get vai srv lookup.
    Say I have this task
    [@temp3]$ dig +short server.test.marathon.mesos
    192.168.123.101
    192.168.124.50
    192.168.124.52
    192.168.124.51
    192.168.123.100
    192.168.123.102
    [@temp3]$ dig +short srv _http-apps._server.test._tcp.marathon.mesos
    0 1 31024 server.test-usbzr-s3.marathon.mesos.
    0 1 31852 server.test-z9x84-s3.marathon.mesos.
    0 1 31790 server.test-k7g8r-s4.marathon.mesos.
    [marc@os0 temp3]$ dig +short srv
    _http-demo._server.test._tcp.marathon.mesos
    0 1 31791 server.test-c8g8b-s4.marathon.mesos.
    0 1 31025 server.test-wtbza-s3.marathon.mesos.
    0 1 31853 server.test-d0x87-s3.marathon.mesos.
    I would like to only make available the ip addresses that are in the
    same range. If I would use a cname like this:
    server.local. CNAME server.test.marathon.mesos.
    I would get 6 of which 3 ip addresses are not in the same range. So I
    need to have something like
    server.local. ??? _http-apps._server.test._tcp.marathon.mesos.
    Is this possible in bind-9.8.2-0.68.rc1.el6_10.3.x86_64?
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  • From Dave Warren@dw@thedave.ca to bind-users on Fri Aug 21 22:00:25 2020
    From Newsgroup: comp.protocols.dns.bind

    On 2020-08-21 16:26, Marc Roos wrote:
    Is it possible to use srv lookups, like eg cname. I do not want to
    create SRV record, I just want to 'get' the ip addresses, that I would
    get vai srv lookup.

    I don't think so, nor does it seem to make sense to me that you would
    want such a thing (in the general case, you may have a use-case).

    SRV records are more than just pointers to a specific server, there is
    also the priority and weight that need to be considered at the
    application level.

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  • From Marc Roos@M.Roos@f1-outsourcing.eu to bind-users on Sat Aug 22 11:45:01 2020
    From Newsgroup: comp.protocols.dns.bind


    I don't think so, nor does it seem to make sense to me that you would
    want such a thing (in the general case, you may have a use-case).
    What would be better way to solve this then? To filter out only the ip addresses that are in the same netmask?
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  • From John Levine@johnl@iecc.com to bind-users on Tue Aug 25 22:43:54 2020
    From Newsgroup: comp.protocols.dns.bind

    In article <mailman.838.1598399252.942.bind-users@lists.isc.org> you write:
    [@temp3]$ dig +short srv _http-apps._server.test._tcp.marathon.mesos
    0 1 31024 server.test-usbzr-s3.marathon.mesos.
    0 1 31852 server.test-z9x84-s3.marathon.mesos.
    0 1 31790 server.test-k7g8r-s4.marathon.mesos.

    These SRV records say that the service is on ports 31024, 31852, and 31790 on the respective servers. CNAME does not give you a port number. There is no way to fake SRV using CNAME.

    R's,
    John
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