I did some more poking around.
I deleted IPsec Configuration and created a new one (name ipsTardis).
I deleted and added the presharedkey.
I deleted and recreated L2TP Configuration (name mobile).
The error in the log remains the same:
daemon.info ipsec: 07[IKE] unable to resolve %any, initiate aborted
Changing the parameter "Secret's ID Selector" to the actual IP of the client also leads to
daemon.info ipsec: 07[IKE] unable to resolve %any, initiate aborted
"Secret's ID Selector" is now set to %any
Manually starting the ipsec service from cli leads to log below.
Any help is greatly appreciated!
Tue Aug 17 16:13:40 2021 authpriv.info ipsec_starter[23377]: Starting strongSwan 5.6.2 IPsec [starter]...
Tue Aug 17 16:13:40 2021 daemon.err modprobe: ah4 is already loaded
Tue Aug 17 16:13:40 2021 daemon.err modprobe: esp4 is already loaded
Tue Aug 17 16:13:40 2021 daemon.err modprobe: ipcomp is already loaded
Tue Aug 17 16:13:40 2021 daemon.err modprobe: xfrm4_tunnel is already loaded
Tue Aug 17 16:13:40 2021 daemon.err modprobe: xfrm_user is already loaded
Tue Aug 17 16:13:40 2021 daemon.info ipsec: 00[DMN] Starting IKE charon daemon (strongSwan 5.6.2, Linux 3.18.44, mips)
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[CFG] loading ca certificates from '/etc/ipsec.d/cacerts'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[CFG] loading aa certificates from '/etc/ipsec.d/aacerts'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[CFG] loading ocsp signer certificates from '/etc/ipsec.d/ocspcerts'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[CFG] loading attribute certificates from '/etc/ipsec.d/acerts'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[CFG] loading crls from '/etc/ipsec.d/crls'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[CFG] loading secrets from '/etc/ipsec.secrets'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[CFG] loaded IKE secret for %any
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[LIB] loaded plugins: charon aes des sha2 sha1 md5 random nonce x509 revocation constraints pubkey pkcs1 pkcs8 pgp pem gmp xcbc hmac kernel-netlink resolve socket-default stroke updown xauth-generic
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 00[JOB] spawning 16 worker threads
Tue Aug 17 16:13:41 2021 authpriv.info ipsec_starter[23396]: charon (23397) started after 400 ms
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 05[CFG] received stroke: add connection 'ipsTardis'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 05[CFG] added configuration 'ipsTardis'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 05[CFG] received stroke: initiate 'ipsTardis'
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 05[IKE] unable to resolve %any, initiate aborted
Tue Aug 17 16:13:41 2021 daemon.info ipsec: 05[MGR] tried to checkin and delete nonexisting IKE_SA
Tue Aug 17 16:13:42 2021 local1.info gsmd[5184]: gsmd send: 'AT+CREG?' (9)
Tue Aug 17 16:13:42 2021 local1.info gsmd[5184]: gsmd get: '+CREG: 2,1,"FFFE","140BA02",7' (29)
Tue Aug 17 16:13:42 2021 local1.info gsmd[5184]: gsmd send: 'AT+ICCID' (9)
Tue Aug 17 16:13:42 2021 local1.info gsmd[5184]: gsmd get: 'ICCID: xxxxxxxxxxxxxxxx' (27)
Tue Aug 17 16:13:42 2021 local1.notice fwblock[23444]: Started fwblock
Tue Aug 17 16:13:42 2021 local1.notice fwblock[23444]: Applying SSH blocks
Tue Aug 17 16:13:42 2021 local1.notice fwblock[23444]: Applying WebUI blocks
Tue Aug 17 16:13:42 2021 user.notice chilli: Stoping chilli.
Tue Aug 17 16:13:42 2021 user.notice chilli: Start
Tue Aug 17 16:14:11 2021 daemon.info ipsec: 09[CFG] received stroke: initiate 'ipsTardis'
Tue Aug 17 16:14:11 2021 daemon.info ipsec: 09[IKE] unable to resolve %any, initiate aborted
Tue Aug 17 16:14:11 2021 daemon.info ipsec: 09[MGR] tried to checkin and delete nonexisting IKE_SA
Tue Aug 17 16:14:24 2021 daemon.err dnsmasq[4962]: failed to send packet: Network is unreachable
Tue Aug 17 16:14:41 2021 daemon.info ipsec: 15[CFG] received stroke: initiate 'ipsTardis'
Tue Aug 17 16:14:41 2021 daemon.info ipsec: 15[IKE] unable to resolve %any, initiate aborted
Tue Aug 17 16:14:41 2021 daemon.info ipsec: 15[MGR] tried to checkin and delete nonexisting IKE_SA