The only one I did differently here was:
•Configure R4 to redistribute the VLAN 43 subnet into EIGRP with the tag value of 4.
SG answer is:
router eigrp 100
redistribute rip metric 100000 100 255 1 1500 route-map RIP_TO_EIGRP
!
ip prefix-list VLAN_43 seq 5 permit 204.12.1.0/24
!
route-map RIP_TO_EIGRP permit 10
match ip address prefix-list VLAN_43
set tag 4
!
route-map RIP_TO_EIGRP permit 20
My config:
router ei 100
redistribute connected metric 100000 1 255 1 1500 route-map VLAN43
route-map VLAN43 permit 10
match interface FastEthernet0/0
set tag 4
On R6:
R6#sh ip route 204.12.1.0
Routing entry for 204.12.1.0/24
Known via "eigrp 100", distance 170, metric 14592
Tag 4, type external