Hi @jfranco
I don’t use Microtik at all, but I can confirm a well working IPsec VPN between OPNsense and NethServer using IKEv2.
I’ll also confirm using much harder encryption than your settings. I do not use 3DES for several years now. I use AES256, SHA512 and more…
And it all works very stable, no issues even when using a Dynamic IP on one side (DynDNS).
I can also confirm a IPsec connection to a SonicWall firewall from NethServer.
My 2 cents
Andy
Note:
A very old Pentium CPU takes about 4-6 hours to brute-force crack a 3DES encryption. Newer CPUs take less than an hour! Even in the year 2000, 3DES was considered insecure, even though a lot of devices still include it in the encryptions as an option. 3DES was once (a very long time ago!) an encryption standard in the US.
So I don’t suggest using 3DES at all!