I am trying to set up IPsec between my home router (an RB4011) and a VPN server configured using Algo (https://github.com/trailofbits/algo).
The server is configured to only accept AES-256-GCM with SHA-512 and ECP384.
I have added the following IPsec profile:
name="algo-profile" hash-algorithm=sha512 enc-algorithm=aes-256 dh-group=ecp384 lifetime=1d proposal-check=obey nat-traversal=yes dpd-interval=2m dpd-maximum-failures=5
RouterOS does initiate an SA with the server, however it proposes AES-256-CBC rather than AES-256-GCM, which of course the server then rejects.
How do I make RouterOS select the correct cipher mode (GCM instead of CBC)?