R1#sh run int e 0/1
Building configuration...

Current configuration : 224 bytes
!
interface Ethernet0/1
 ip address 17.100.1.1 255.255.255.0
 ip pim query-interval 90
 ip pim sparse-dense-mode
 ip multicast helper-map 224.1.1.1 17.100.1.255 100
 ip igmp query-interval 90
 half-duplex
 no keepalive
end


R2(config-if)#do sh run int fa 0/1
Building configuration...

Current configuration : 173 bytes
!
interface FastEthernet0/1
 ip address 180.40.7.98 255.255.255.224
 ip pim sparse-dense-mode
 ip multicast helper-map broadcast 224.1.1.1 100
 duplex auto
 speed auto
end

R2(config-if)#

On both routers:

access-list 100 permit udp any any eq tftp