Failed to start Internet Key Exchange (IKE) Protocol Daemon for IPsec error, how to fix it?

Question

CentOS

Failed to start Internet Key Exchange (IKE) Protocol Daemon for IPsec error, how to fix it?

● ipsec.service - Internet Key Exchange (IKE) Protocol Daemon for IPsec
   Loaded: loaded (/usr/lib/systemd/system/ipsec.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Wed 2020-12-23 11:33:14 MSK; 1h 7min ago
     Docs: man:ipsec(8)
           man:pluto(8)
           man:ipsec.conf(5)

Dec 23 11:33:14 appliance systemd[1]: ipsec.service: Service RestartSec=100ms expired, scheduling restart.
Dec 23 11:33:14 appliance systemd[1]: ipsec.service: Scheduled restart job, restart counter is at 5.
Dec 23 11:33:14 appliance systemd[1]: Stopped Internet Key Exchange (IKE) Protocol Daemon for IPsec.
Dec 23 11:33:14 appliance systemd[1]: ipsec.service: Start request repeated too quickly.
Dec 23 11:33:14 appliance systemd[1]: ipsec.service: Failed with result 'exit-code'.
Dec 23 11:33:14 appliance systemd[1]: Failed to start Internet Key Exchange (IKE) Protocol Daemon for IPsec.
Dec 23 11:33:18 appliance systemd[1]: ipsec.service: Start request repeated too quickly.
Dec 23 11:33:18 appliance systemd[1]: ipsec.service: Failed with result 'exit-code'.
Dec 23 11:33:18 appliance systemd[1]: Failed to start Internet Key Exchange (IKE) Protocol Daemon for IPsec.

PLEASE, HELP !

Answer 1

The log from systemd is completely useless (like systemd itself), you need the log of the ike daemon itself - what do you have there - strongswan?