I don't understand why we can't use:
router ospf 1
distance ospf external 171
on sw2 and r3. In the solutions it says that:
"SW2’s EIGRP adjacency to become active after it has learned the RIP prefixes from OSPF (redistributed by R3)."
If the AD was set to 171 for ospf external on sw2 wouldn't sw2 still prefer eigrp external routes with AD 170?