Forum Discussion

  • Thanks for the response. I have an F5 Loadbalancer configured on Amazon EC2. I am trying to configure the pools to resolve to an ELB CNAME. For some reason when i give the came address of the ELB in the pool hostname, its resolving to a single ip of ELB . As you know the ELP ip's are dynamic and changes as ELB Scales UP/Down. Also there are 3 IP's for ELB if its distributed to multiple AZ's. How can i configure my pool to resolve to all 3 IP's and dynamically update when the ip changes.

     

  • Sorry for the delay.

     

    OK, so in essence (I know next to nothing about AWS and ELB) you are trying to configure Pool Members using a DNS name rather than an IP address? I'm pretty sure that's not possible.

     

    Possibly you could use iCall or iControl to do something interesting here or even a bash script. Not sure what your skills are like in these areas and how you might 'discover' when instances are spun up and down and also what IPs are in use (although the latter should be relatively simple I suppose).

     

  • You're looking for integration with AWS that f5 does not provide. You could write a script that updates the BIG-IP pool list based on the query response for the ELB IP to cover your use case. You might also consider using our GTM solution instead of the ELB.

     

  • thanks @Daniel. we cannot use the GTM/LTM as a replacement for ELB, since that doesn't automatically add the new servers when a instance boots up

     

    • joeldavism's avatar
      joeldavism
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      Not able to open this article. Getting page cannot be found. Anyone around who can share the new link?

  • Hi John, Thanks for the response. The article is great. However we are trying to have the ELB's added to our LTM.Is there any way to add ELB cnames to LTM ?

     

  • Tito, I don't know if there's a way to do this with just the LTM. I can ask around and post on here if I find a way to achieve this with just LTM.

     

  • Check out this new feature in 11.6.0: You can configure a BIG-IP system with nodes and pool members that are identified with fully-qualified domain names (FQDNs). When you configure pool members with FQDN, addresses will dynamically follow DNS changes. Fully dynamic DNS-managed pools may even be created. In the following illustration, the BIG-IP Local Traffic Manager creates an ephemeral pool member for each IP address returned in the DNS response.

     

    https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-implementations-11-6-0/32.print.html