Symptom
Below error logs are observed on ISR4300
%ATTN-3-SYNC_TIMEOUT: msecs since last timeout 60153, missing packets 999
%ATTN-3-SYNC_TIMEOUT: msecs since last timeout 610824, missing packets 1189
%ATTN-3-SYNC_TIMEOUT: msecs since last timeout 610824, missing packets 11898
Conditions
ISR4300 running IOS-XE 17.6.x + IPSec anti-replay errors.
%IPSEC-3-REPLAY_ERROR: IPSec SA receives anti-replay error, DP Handle 3, src_addr x.x.x.x, dest_addr w.x.y.z, SPI 0x997978db
Workaround
- Configure logging discriminator to drop those logs on the router.
Further Problem Description
Only on ISR4300.
When anti-replay report out of window packet drop, ATTEN-SYNC_TIMEOUT will also be triggered.
This is false alarm.
