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eNomineZerum_31's avatar
eNomineZerum_31
Icon for Nimbostratus rankNimbostratus
Sep 11, 2017

Upgrading and Replacing aged GTMs in multiple data centers

Hi all,

 

I have been tasked to replace two aging GTMs in two separate data centers. They are operating stand alone but are performing zone transfers to each other.

 

One is being totally decommed (as we are turning up a GTM in a 3rd DC) and the other is simply being replaced with new hardware.

 

The problem comes in that I know nothing of GTMs and very little on DNS. My F5 knowledge comes from upgrading F5s that run LTM and supporting them.

 

What would be the most efficient way to go about this task?

 

So far I have the following:

 

  • Upgrade existing GTMs to current code
  • Ensure replacement devices are on current code
  • Stand up New GTM and perform zone transfer to it
  • Shutdown GTM that will be replaced with new hardware
  • Replace shutdown GTM with new hardware
  • Decomm GTM that ISN'T being replaced

I think my logic is sound enough as we will have continuous DNS capabilities and not drop below 2 active devices at any given time.

 

However, I don't know the pitfalls, am unsure of how to set up DNS transfer (we are running BIND) and overall don't know the best way forward.

 

Thanks in advance for any assistance!

 

application delivery
BIG-IP DNS
big-ip gtm
software upgrade

1 Reply

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  • Leonardo_Souza's avatar
    Leonardo_Souza
    Icon for Cirrocumulus rankCirrocumulus
    Sep 11, 2017

    It is going to be a challenge for you to do this without knowing DNS protocol, and only with LTM knowledge. As GTM functions totally different than LTM.

     

    The zone transfer is done automatically by the GTMs, as long as you have the checkbox to synchronize the DNS zone files. In v13 the option is:

     

    DNS > Settings > GSLB > General

     

    GTM itself is always standalone but can be in a sync group with other GTMs. However, they are all standalone and active.

     

    If a new GTM, configure the base config, create the GTM server object in the existing GTM to represent this new GTM, do a gtm_add after. Very import, gtm_add from the new GTM to point to the OLD GTM.

     

    If you are replacing a GTM with the same IPs, configure the base config, do a gtm_add after. Very import, gtm_add from the new GTM to point to the OLD GTM. Don't forget to configure the replacement GTM out of the network, and then shutdown the old one and connect the new one.

     

    I hope this gives you some ideas. Better you try this in a lab environment before.

     

    gtm_add solution:

     

    https://support.f5.com/csp/article/K13312