With CSM the only way to achieve ACtive/Active redundancy is using RHI (Route health injections). You can configure CSMs such that CSMs inject "high cost" host routes for VIP1 (on CSM1) and "low cost" routes for VIP1 (on CSM2) to MSFC.

Similarly for another VIP say VIP2, CSM will inject "high cost" host routes for VIP2 (on CSM2) and "low cost" routes for VIP2 (on CSM1) to MSFC.

This way both CSMs will be active (but for different VIPS).

The most important thing with this design is to ensure that the return traffic hit the correct CSM.To achieve this you can use policy based routing.

Traditional CSM redundancy uses HSRP and hence one CSM is active at a time.

Syed