Can I use nested DNS wildcard records











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I would like to have multiple dns entries with wildcards such that one entry is nested as subdomain of another



CNAME *.example.com -> webserver.example.com
CNAME *.api.example.com -> apiserver.example.com


The intention being that I can use customer.example.com to access the webserver and customer.api.example.com to access the api server.



Since customer.api.example.com is a valid match for both of the wildcard entries i'm not sure how this will get resolved.



I have tested this on AWS route53 as the DNS provider and it seems to work as expected.customer.api.example.com resolved to the api server. But i'm not sure if this is guaranteed by the DNS spec or was just chance it picked the correct server.



Is this behaviour something I can rely on to be consistent?










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    up vote
    3
    down vote

    favorite
    1












    I would like to have multiple dns entries with wildcards such that one entry is nested as subdomain of another



    CNAME *.example.com -> webserver.example.com
    CNAME *.api.example.com -> apiserver.example.com


    The intention being that I can use customer.example.com to access the webserver and customer.api.example.com to access the api server.



    Since customer.api.example.com is a valid match for both of the wildcard entries i'm not sure how this will get resolved.



    I have tested this on AWS route53 as the DNS provider and it seems to work as expected.customer.api.example.com resolved to the api server. But i'm not sure if this is guaranteed by the DNS spec or was just chance it picked the correct server.



    Is this behaviour something I can rely on to be consistent?










    share|improve this question







    New contributor




    Dave Turvey is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.






















      up vote
      3
      down vote

      favorite
      1









      up vote
      3
      down vote

      favorite
      1






      1





      I would like to have multiple dns entries with wildcards such that one entry is nested as subdomain of another



      CNAME *.example.com -> webserver.example.com
      CNAME *.api.example.com -> apiserver.example.com


      The intention being that I can use customer.example.com to access the webserver and customer.api.example.com to access the api server.



      Since customer.api.example.com is a valid match for both of the wildcard entries i'm not sure how this will get resolved.



      I have tested this on AWS route53 as the DNS provider and it seems to work as expected.customer.api.example.com resolved to the api server. But i'm not sure if this is guaranteed by the DNS spec or was just chance it picked the correct server.



      Is this behaviour something I can rely on to be consistent?










      share|improve this question







      New contributor




      Dave Turvey is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      I would like to have multiple dns entries with wildcards such that one entry is nested as subdomain of another



      CNAME *.example.com -> webserver.example.com
      CNAME *.api.example.com -> apiserver.example.com


      The intention being that I can use customer.example.com to access the webserver and customer.api.example.com to access the api server.



      Since customer.api.example.com is a valid match for both of the wildcard entries i'm not sure how this will get resolved.



      I have tested this on AWS route53 as the DNS provider and it seems to work as expected.customer.api.example.com resolved to the api server. But i'm not sure if this is guaranteed by the DNS spec or was just chance it picked the correct server.



      Is this behaviour something I can rely on to be consistent?







      domain-name-system wildcard-subdomain






      share|improve this question







      New contributor




      Dave Turvey is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|improve this question







      New contributor




      Dave Turvey is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|improve this question




      share|improve this question






      New contributor




      Dave Turvey is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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      asked Nov 29 at 11:36









      Dave Turvey

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      New contributor





      Dave Turvey is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






      Dave Turvey is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






















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          This approach is ok, DNS server use the most specific match which is *.api.example.com for customer.api.example.com The behavior should be consistent because is defined in RFC 1034






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            1 Answer
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            active

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            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes








            up vote
            5
            down vote



            accepted










            This approach is ok, DNS server use the most specific match which is *.api.example.com for customer.api.example.com The behavior should be consistent because is defined in RFC 1034






            share|improve this answer

























              up vote
              5
              down vote



              accepted










              This approach is ok, DNS server use the most specific match which is *.api.example.com for customer.api.example.com The behavior should be consistent because is defined in RFC 1034






              share|improve this answer























                up vote
                5
                down vote



                accepted







                up vote
                5
                down vote



                accepted






                This approach is ok, DNS server use the most specific match which is *.api.example.com for customer.api.example.com The behavior should be consistent because is defined in RFC 1034






                share|improve this answer












                This approach is ok, DNS server use the most specific match which is *.api.example.com for customer.api.example.com The behavior should be consistent because is defined in RFC 1034







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Nov 29 at 11:47









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