I have a dual-hub mGRE network setup over an MPLS network. I am using EIGRP for routing and it generally seems to be working well as far as data and routing go. VoIP is another matter. We are seeing inconsistent reports on call quality. We have QoS setup with service provider and on mGRE tunnels. Since all traffic goes over MPLS we are not using IPSec. Utilization on the circuits is very low. Most circuit usually run only 20-40% utilization.
So I start digging around and found two things that seem odd:
1) When I do "sho ip nhrp" I notice most of the registrations have the NAT flag set. This I find out because there is no NATTing being done anywhere.
2) NHRP registration routinely counts down to 0:00 before re-registering. I was under the impression that a client will refresh its registration at 1/3 interval of nhrp holdtime but this doesn't seem to be working. I currently have holdtime set at 28800 because all IPs are static. I have tried other holdtime settings and also tried setting the ip nhrp registration timeout but registration still counts down to 0:00.
Should I be worried about this? Or should I keep looking for another problem?