Not trying to high jack this post, but have a similar issue. i have a 460 with pim sparse to a external RP off my network. i pull 324 multicast via this sparse vlan. the rest of my network is currently dense, working as it is , i want to convert my entire network from dense to all sparse. which will cause me to have a different RP on my own network. could i use this same inter-VR solution to pass multicast from my current sparse VR to a new separate VR sparse ring? i was kind of thinking of using MSDP. thanks in advance,