Сабж.
Просто не подключается и все. Через службу strongswan-starter тоже:
● strongswan-starter.service - strongSwan IPsec IKEv1/IKEv2 daemon using ipsec.conf
Loaded: loaded (/lib/systemd/system/strongswan-starter.service; disabled; vendor preset: enabled)
Active: active (running) since Fri 2022-03-11 12:18:23 MSK; 49s ago
Main PID: 14503 (starter)
Tasks: 18 (limit: 18398)
Memory: 4.5M
CGroup: /system.slice/strongswan-starter.service
├─14503 /usr/lib/ipsec/starter --daemon charon --nofork
└─14517 /usr/lib/ipsec/charon
мар 11 12:18:23 alex-thinkpad charon[14517]: 07[ENC] generating IKE_SA_INIT request 0 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(FRAG_SUP) N(HASH_ALG) N(REDIR_SUP) ]
мар 11 12:18:23 alex-thinkpad charon[14517]: 07[NET] sending packet: from 192.168.13.12[500] to XXX.XXX.XX.XXX[500] (1128 bytes)
мар 11 12:18:27 alex-thinkpad charon[14517]: 14[IKE] retransmit 1 of request with message ID 0
мар 11 12:18:27 alex-thinkpad charon[14517]: 14[NET] sending packet: from 192.168.13.12[500] to XXX.XXX.XX.XXX[500] (1128 bytes)
мар 11 12:18:34 alex-thinkpad charon[14517]: 07[IKE] retransmit 2 of request with message ID 0
мар 11 12:18:34 alex-thinkpad charon[14517]: 07[NET] sending packet: from 192.168.13.12[500] to XXX.XXX.XX.XXX[500] (1128 bytes)
мар 11 12:18:47 alex-thinkpad charon[14517]: 07[IKE] retransmit 3 of request with message ID 0
мар 11 12:18:47 alex-thinkpad charon[14517]: 07[NET] sending packet: from 192.168.13.12[500] to XXX.XXX.XX.XXX[500] (1128 bytes)
мар 11 12:19:10 alex-thinkpad charon[14517]: 06[IKE] retransmit 4 of request with message ID 0
мар 11 12:19:10 alex-thinkpad charon[14517]: 06[NET] sending packet: from 192.168.13.12[500] to XXX.XXX.XX.XXX[500] (1128 bytes)
При этом просто через charon-cmd все отлично работает.
В dmesg ругался apparmor. Я его вообще отключил - это не помогло.