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Jason_Brooks
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Feb 24, 2021

dns transparent cache as authoritative?

Hello,

 

I have inherited an f5 pair that is (in theory) an authoritative-only name server. it has a pool of three dns servers it passes queries to.

 

The first lookup using the f5 as the dns server has the authoritative bit set. However, subsequent queries (cache hit) do not, until the ttl time has elapsed. In other words, it acts as a standard dns caching server that sets authoritative when it has to query an authoritative server for an answer.

 

Is there a way to set up the F5 with this configuration to always answer authoritative?

 

bigip version 15.1.0.5

 

udp listener with dns profile name: "authoritative_dns"

 

authoritative_dns profile set:

parent == dns

dns express enabled

dns cache enabled: set to "authoritative_cache"

authoritative_cache set:

resolver type: transparent (NONE)

1 Reply

  • I don't think this possible as F5 may have not implemented this to not violate the DNS standards. You can configure DNS Express zone and in this way the f5 will be slave zone authorative DNS server:

     

    https://techdocs.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/dns-services-implementations-11-5-0/1.html