[c-nsp] RP Migration option

[Андрей Андреев]

Hi List,

Please advise me how can i use two independent RP at network for same 
groups to smoothly migrate backbone/aggregation devices and client 
equipment to new RP.

We have large network and even more large clients connected via PIM.
Now all network use static RP address from our partner AS.
We use PIM to connect to this partner.

Recently we start to use MSDP and MBGP at network edge device.
We received RP address and multicast source addresses via MBGP for RPF 
check and MSDP also works fine.

I plan to make Anycast RP on this edge device and change RP mapping on 
whole network.
Is there is any way to do this smoothly?
I can take window time and change RP at once on my device, but many 
clients cant do this.
So i need a way to migrate sequentially or partially over the long time.

One good news, Old RP address located beyond the edge router with 
MSDP/MBGP sessions so RPF is completely identical from view of whole 
network.

Backbone and edge run at 7600 - Sup720
Aggregation ran at 3560/3750

Any opinions and suggestions are welcome.