Hello,
You can make use of the below link:
https://kb.juniper.net/InfoCenter/index?page=content&id=KB8157&actp=search
Note:- That link talks about accessing same MIP from Internet and loopback. Same principle should apply for accessing MIP from two different tunnels.
Try to do something like this:
Let us say ethernet1 terminates ISP1. It is end point of one tunnel with its tunnel interface tunnel.1
And ethernet2 terminates ISP2. It is end point of another tunnel with its tunnel interface tunnel.2.
Configure MIP for loopback.1
Now put eth1, eth2, tunnel.1, tunnel.2 & loopback.1 in untrust zone.
put tunnel.1 and tunnel.2 in loopback-group loopback.1.
Regards,
Rushi