Hi, we have got a ISR4331/K9 with IOS XE 15.5(3)S4b showing the same log:
Oct 15 13:54:01.714: %IOSXE-3-PLATFORM: SIP1: cpp_cp: QFP:0.0 Thread:000 TS:00001842578982784425 %IPSEC-3-REPLAY_ERROR: IPSec SA receives anti-replay error, DP Handle 28, src_addr 172.29.250.39, dest_addr 172.29.250.30, SPI 0x46953b0e
We suppose bug CSCtz84561 is affecting to us, so please could you tell my which IOS XE versión would solve the problem?