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JG's avatar
JG
Icon for Cumulonimbus rankCumulonimbus
Feb 10, 2015

Pool members with fully-qualified domain names (FQDNs): How does this work?

From release notes of v11.6.0 (on new features):   Populate pools by FQDN This release includes the ability to configure a BIG-IP system with nodes and pool members that are identified with fully...
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Brad_Parker_139's avatar
Brad_Parker_139
Icon for Nacreous rankNacreous
Feb 11, 2015

The FQDN node list will auto populate all the nodes that are returned by the DNS query; they are called ephemeral nodes. You need to make sure your DNS server is set to return all A records for this to occur.

 

  • JG's avatar
    JG
    Icon for Cumulonimbus rankCumulonimbus
    Feb 11, 2015
    Thanks for your response. Does this mean that the total or maximum number of pool members/nodes is determined from the initial DNS query of the fqdn made at the time of pool creation, i.e. the number of A records returned? And just how ephemeral are these pool members/nodes? Are all subsequent DNS queries based on the TTL of the records? There should be a sol article to give us more details about this.
  • Brad_Parker_139's avatar
    Brad_Parker_139
    Icon for Nacreous rankNacreous
    Feb 11, 2015
    I've actually been playing with this in our test environment. The nodes will be created at the time of the original DNS query, however you can configure the LTM to auto populate and you can choose the interval that the LTM re-queries DNS. By default auto populate is on and re-checks once an hour. If an IP is not returned that was originally it will be removed and subsequently, if a new IP is returned it will be added. I hope this helps. https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-implementations-11-6-0/32.print.html