Recently I enabled a multicast group to connect to a different rp-address. Following that all subscriber traffic was via the new rp. However, I had a problem and as a result I had to disable this new rp setup. I removed the rp configuration from the switch i.e "no ip pim rp-address 10.20.3.2 WAN-GROUPS". After this I looked at the output from "show ip mroute" and I saw the traffic was still being sent via the new rp.
Can someone explain this, do I need to reload or clear some table?
The multicast streams will stay in place until they age out, although it will not make much of a difference as with default settings the multicast tree will change to source based anyway.
If you need to see a difference try 'clear ip mroute *'
(or you can use the same command but specify the particular groups)