Can you provide more information, this might be a DDTS, what steps have you taken so far, when mvpn stops working,can you confirm if the mdt tunnel is up? can you see the mroute for that group? Can you run debug. I have a feeling this might be a bug, I know i have seen similar issue on GSR, but the corruption was the MDS (Multicast Distributed Switching). Not sure how 7200 platform does the MDS.
the problem is with the cisco ios becasue by default mpls doesnot support multicast for its support need to run mdt and mdt works over GRE, actually that GRE goes hang just becasue of that yu are facing the problem. Once you delete it and create it the new gre comes up and your mdt works again. Same problem we are facing in our cloud but yet to get the workaround.
It has nothing to do with Cisco IOS not support mpvn natively, this is every platform, currently everyone uses Rosen-draft, which is building mgre. that been said. i m not expert on 7200, but it seems to be a bug, example, on a GSR, when you create MDT, the RP, sends the tunnel IDB HW to the Line Card and sometimes that could be a problem. So i would advise the original poster to get with Cisco and make sure you are not hitting DDTS
Introduction: The "external-out enable" command is available for
configuration under the "router ospf process" in case of the IOS-XR
operating system. This command basically enables advertisement of
intra-area routes on the device as external routes in th...
Introduction Basic configuration for netflow Scale parameters for
netflow Netflow support Architecture Packet flow for netflow Inside the
LC CPU Netflow Cache size, maintenance and memory Sample usage Cache
Size Aging Permanent cache Characteristics Which...