can i have both static routes and eigrp configured to same route? When does moving to eigrp add value?

Is there a way/command to look up a the router name and interface number by an ip address.

I am having what seems to be routing issues between vlans on the central office to the branch office. No network changes were made to cause this. And everything the ISP has checked is OK. It looks normal everywhere also so I have done a packet captu...