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faizan123_23330's avatar
faizan123_23330
Icon for Nimbostratus rankNimbostratus
Sep 08, 2017

Fail-over | config Sync on F5

Hi, We are using the F5 LTMs 2000s in our production environment Both are in active standby state. we want to upgrade its version from 11.2.1 to 11.6.1. Our client has raised a query with us if we upgrade a one F5 unit to the 11.6.1 and leave the other unit to the previous one (11.2.1).

 

Does it have any impact on the production traffic?

 

What kind of issue arise during the failover? is the failover perform smoothly ?

 

Is the configurations sync with the other unit during this interval ?

 

Kindly comment on this.

 

application delivery
BIG-IP
LTM

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  • Martijn_van_de1's avatar
    Martijn_van_de1
    Icon for Cirrus rankCirrus
    Sep 08, 2017

    Hi,

     

    Yes you can leave one appliance on 11.2.1 and the other on 11.6.1, but I would not advise that. Below a F5 statement:

     

    "Note: When upgrading a device group from version 11.x, or later, software to the latest version software, mirroring does not function until all devices in the device group complete rebooting to the latest version."

     

    So you must take into account sessions are lost during fail-over when both devices have different versions. Thats why F5 recommends a window when upgrading.

     

    "F5 Networks® recommends upgrading software during a scheduled maintenance window, to minimize traffic disruption when devices run different software versions."

     

    I have seen issues with sync when both devices have different software version, so I strongly advise to upgrade all devices in the same cluster to the same version.

     

    On you can find plenty of information and documentation about upgrading Active/Standby cluster. Complete with all the steps that are needed.

     

    And you should have good test procedures you can perform before and after the upgrade.

     

    Good luck.

     

    Martijn.