Hi,
We are facing with one of Hub to Spoke DMVPN connectivity as IPSEC tunnel is not coming up. While troubleshooting spoke is not able to reach DMVPN tunnel ip address of hub & hub is not able to reach tunnel ip address of Spoke. Tunnel status is showing up on both hub & spoke side.
Please let me know what can be the possible cause of the issue. Tunnel was a working tunnel which got suddenly went down.
Also please share DMVPN debugging commands which can be used in production network & is less router impact.