Libreswan L2TP/IPsec Not Working

Hi, I want to install L2TP on my OpenWrt installed in digitalocean VPS to be use in my Mikrotik router.

The instruction from the Libreswan L2TP/IPsec wiki seems to have some deprecated/invalid package.

Unknown package 'ipsec-tools'.
Unknown package 'kmod-crc-ccitt'.
Unknown package 'kmod-crc16'.
Unknown package 'kmod-crypto-aes'.
Unknown package 'kmod-crypto-core'.
Collected errors:
 * opkg_install_cmd: Cannot install package ipsec-tools.
 * opkg_install_cmd: Cannot install package kmod-crc-ccitt.
 * opkg_install_cmd: Cannot install package kmod-crc16.
 * opkg_install_cmd: Cannot install package kmod-crypto-aes.
 * opkg_install_cmd: Cannot install package kmod-crypto-core.

However, I manage to install ipsec-tools manually from third party repository (ipsec-tools.ipk) form pkgs.org. But, I can't find where to download the kmod* packages.

In despite of the missing dependencies, I continued the installation process but I could not connect from the client side. Firewalls are already configured (ESP, AH and necessary port).

PPTP VPN server barely works because I have one of my 2 Mikrotik router can not connect (I can't figure out why) as well as my ubuntu pc. Android and my OpenWrt router can connect easily. Also PPTP speed is too slow.

OpenVPN server in the other hand works pretty much but Mikrotik needs username (auth-user-pass) in order to connect but I can't figure out how to have auth-user-pass on server. All tutorials in the internet uses "nopass".

I am new to this so I hope you'll understand my errors.

Kernel module packages need to match the running kernel exactly (having been part of the same kernel-/ image build), you can't find them from third party sources. IPsec builds strongly on kernel integration, for OpenWrt the userspace tools are provided by strongswan (and it works).

If you can, have a look at wireguard instead, which tends to be easier to set up and work with.

Wireguard may not be a solution yet because when I successfully configured wireguard server and successfully connected to my Mikrotik, after an OpenWrt Server reboot, I cannot connect again. Also, I am stuck in single user mode. I still can't figure out how to have multi user on openwrt/wireguard server. I only discovered wireguard just yesterday.

One thing I may not use it is, I cannot ssh my mikrotik from Openwrt shell unlike pptp vpn.

Also, I just found out that on my current ISP, I can connect to pptp but my second ISP can not. Maybe that's the reason why one of my mikrotik couldn't connect to pptp. L2TP/IPSec, as I can say, is the ideal vpn for my setup.