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Ireda's avatar
Ireda
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Feb 19, 2024

GTM Design | LTM+ ASM+GTM on same VM

Dears, I am planning to publish the same service through two sites by LTM and ASM. Each site has two F5 VMs (LTM and ASM).   The customer is required to make the two sites active-active, we recomm...
  • Amine_Kadimi's avatar
    Feb 21, 2024

    Hi,

    My answers based on a few similar projects:

    1- You can have one GTM, but it won't provide true NS redundancy. Best practice I've seen is to have at least two NS geographically separated, each NS pointing to a GTM cluster (2VMs per site to provide in-site F5 redundancy). Other advanced architecture have more NS but same number of F5s by adding secondary ISP link to the mentioned GTMs

    2- In theory you can have the three modules in the same VM (I recommend 16GB of RAM) but in practice it's better to have GTM in a separated VM and separated subnet.

    3- There's two parts: where to position GTM? and how to handle DNS requests? For the first I usually prefer to have DNS as close as possible to the WAN edge router. For the second, you usually delegate a subdomain, or if managing all your domain by GTM you can point the entire domain to your GTM listeners

    4- Two IPs, one for each ISP