The error %OSPF-5-ADJCHG: Process ID , Nbr [ip-address] on GigabitEthernet 1/0/3 from FULL to DOWNis caused due to Bidirectional Forwarding Detection (BFD) errors. BFD can potentially generate false alarms-signaling a link failure when one does not exist.
The timers used for BFD are so intensive CPU cycle, or a brief interval of data corruption or queue congestion could potentially cause BFD to miss enough control packets to allow the detect-timer to expire. The Minimum Transmit Interval, Minimum Receive Interval and Multiplier are recommended to be set as 100 100 3 respectively. Configuring process-max-timer 50 is also recommended to prevent unpredictable CPU unavailability.