why the ip mroute on R2 pointing XR1 loopback through XR2 ?
"ip mroute 10.0.0.19 255.255.255.255 10.0.220.20"
Do a "show ip mroute 10.0.0.19" on R2 and you'll see why this is needed.
Ok the R2 is learning this prefix over the leaking provied by XR2. I got it, since multicast traffic could potentially come from everywhere this is needed. (in all situations or in failure ones).
Also the task states that R6,R7,and R8 should ping all the mcast addresses , but as per the solution this is not the case, R6 can ping everybody but not R7 or R8.
Anyone had similar issues ?