Started after installing the latest version - 23.1.4 (and still happened after 23.1.4_1).
The two IPsec tunnels were rock stable with the previous versions.
The tunnels status is still up on the OPNsense GUI, but I can't ping or SSH to hosts on the other side.
After around 40 minutes I'm getting these entries in the log:
2023-03-27T13:13:02 Informational charon 05[ENC] <con3|25> generating CREATE_CHILD_SA request 8 [ N(REKEY_SA) N(ESP_TFC_PAD_N) SA No KE TSi TSr ]
2023-03-27T13:13:02 Informational charon 05[IKE] <con3|25> establishing CHILD_SA con3{57} reqid 3
2023-03-27T13:13:02 Informational charon 05[KNL] creating rekey job for CHILD_SA ESP/0xec8f744e/167.xxx.xxx.xxx
and then this:
2023-03-27T13:16:11 Informational charon 11[IKE] <con2|24> rekeying IKE_SA failed, peer not responding
2023-03-27T13:16:11 Informational charon 11[IKE] <con2|24> giving up after 5 retransmits
2023-03-27T13:15:47 Informational charon 11[KNL] <con3|25> unable to delete SAD entry with SPI c088053f: No such process (3)
2023-03-27T13:15:47 Informational charon 11[IKE] <con3|25> giving up after 5 retransmits
Only restarting the strongswan service solves the problem.
Any ideas?