Cluster 2 LTMs and keep both configurations sets

Are both BIGIP configured in different networks?

If yes, before merging configuration (which will be done manually from command line), you have to think about design...

The easiest solution to manage this is to work with partitions / route domains : - one partition per environment - vlans are assigned per partition - one route domain per partition - one traffic group per partition (with priority to be active on previous env appliance if both are up)

To configure vlans, configure first with fake vlan ID.

Then in tmsh, you have to copy old configuration

list ltm pool one-line    
list ltm virtual one-line    
list ltm profile one-line    
list ltm monitor one-line    

Copy all configuration returned in a notepad, Remove objects you don’t want to import in the new partition, then import it in new partition:

cd /env1/    
load sys config merge from-terminal    

PASTE HERE THE CONFIGURATION    

END WITH CTRL-D    

To make sure you don’t miss some configuration, you can first import monitors, profiles.. then pools and finally virtual servers