Sometimes my VPN tunnel will become really slow! If you ping tunnel IP the response time is around 3 or 4 seconds. However if you ping the physical interface's IP at the same time the response time is only around 80ms... It only happens at two branches. It only happens once or twice everyday and lasts at most 20 seconds. Other branches are fine. All branches have exactly same configuration.
No related information at all in the logging (logging level is debugging)
No errors at all on phycical or tunnel interface
I am using DMVPN with basic configurations. No QoS configuration at all.
Any advices are appreciated! Thanks!