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?






domain-name-system wildcard-subdomain







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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?






    domain-name-system wildcard-subdomain







    share|improve this question
























      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?






      domain-name-system wildcard-subdomain







      share|improve this question













      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




      domain-name-system wildcard-subdomain






      share|improve this question













      share|improve this question











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      share|improve this question










      asked Nov 29 at 11:36









      Dave Turvey

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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






          share|improve this answer





















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            1 Answer
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            1 Answer
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            active

            oldest

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            active

            oldest

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            active

            oldest

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            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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