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Kun-Te_Chou's avatar
Kun-Te_Chou
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Mar 27, 2018

AWS Auto Scaling for LTM

Hi ALL,

 

After I watched the introduction of AWS Auto Scaling for BIG-IP VE by the following link, I still have one question. https://support.f5.com/csp/article/K60112332

 

According to its explanation, Auto Scaling just like its name, it will help to grow up or even narrow down your monitoring target (either EC2 or BIG-IP VE) without any manual intervention. So my concern is when Auto Scaling creates the 2nd or even the 3rd LTM, do those three LTMs run on the same configuration? If so, what the data flow will be? For instance...

 

  • Who will be assign the request to those LTMs? ELB in this case (2-tiers load-balancing)?
  • How does the member server (node) know its return traffic need to go which LTM?

Appreciate for the confirmation by anyone of you in advance.

 

AWS
cloud
LTM

1 Reply

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  • Jeff_Giroux_F5's avatar
    Jeff_Giroux_F5
    Ret. Employee
    Jan 07, 2020

    The autoscale BIG-IP instances will sync configs. You can review the github templates README for more info on clustering. It happens automatically via CFT template deployment.

     

    https://github.com/F5Networks/f5-aws-cloudformation/tree/master/supported/autoscale/waf/via-lb/1nic/existing-stack/payg

     

    Your questions...

    Who will assign the request to the LTMs?

    -Yes, it will be an ELB in tier 1 doing basic L4 traffic distribution to tier 2 BIG-IP instances.

     

    How does the member server know its return traffic?

    -Each BIG-IP instance has its own IP config. There is no sharing of floating IPs. Therefore, each BIG-IP instance will send traffic to the backend server via its own unique self-IP. Return traffic from server to BIG-IP will talk to the AWS cloud hyervisor and route appropriately to the correct BIG-IP instance.