Enable ECMP Dynamic Rebalance

ECMP dynamic rebalance enables hash-based distribution among the ECMP paths when a new next-hop is added.

Enter global configuration mode.
```
device# configure terminal
```
Enter router PIM configuration mode.
```
device(config)# router pim
```
Enable ECMP load sharing with dynamic rebalance.
```
device(config-pim-router)# rpf ecmp rebalance
```