IKEv2 Vpn connection fails after certificate update

Help
1

Can't connect to VPN on my server, which is using let's encrypt certificates. Yesterday it was working, but since June 18th (when certificate seemed to have updated and changed the certificate chain) I can't connect using either android or linux machines.

Please see connection log provided by android's strongswan.
charon.log.txt (81.9 KB)

My domain is: artunnel.ddns.net

I ran this command: N/A

It produced this output: N/A

My web server is (include version): 152123.nl.web.highserver.ru (don't know the version)

The operating system my web server runs on is (include version): Ubuntu 24.04.4 LTS x86_64

My hosting provider, if applicable, is: Hostin-Russia

I can login to a root shell on my machine (yes or no, or I don't know): yes

I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): 2.9.0

2

Strongswan has a bug where it doesn't use all of the certificates provided in the certificate chain, and so for chains over a certain length it can't validate that the certificate is trusted. These sorts of chains are normal but it has been many years since Let's Encrypt has used them so some people are only hitting a problem recently. I think this recent thread has the most detail and links to the open issue they have:

3

Thank you. I've used the script and the instructions provided. It worked.