So now, with 2.2.5…does L2TP/IPSec work?
Simple question. And is there a guide?
As for "does it work", the general agreement here seems to be that it's not worth the PITA, better to use IKEv2.
Guide is on the wiki linked already. It works in some cases, not in others, all depends on the client. No better or worse on 2.2.5 than other 2.2.x releases. Some clients are OK, others (Like Windows behind) are not.
IKEv2 is the best way forward. Ignore L2TP/IPsec if at all possible.