I was able to successfully connect to the router with L2TP/IPSec Windows builtin client following this setup:
IPSec settings: 3DES encryption, SHA-1 authentication and DH Group 2 for phase 1 and phase 2 , other is default
L2TP Server settings: practically default with PSK(without any special chars, just A-Z,a-z,0-9)
Windows builtin client: general - 22.214.171.124, security - type L2TP/IPSec, data encryption - maximum, allow these protocols - PAP ONLY, networking - IPv4 - advanced properties UNCHECK use default gw on remote network
RV340W is on Firmware Version: 1.0.02.16 so the new GUI
I'm unable either ping nor see the remote subnet network, nor the router's local network IP address.
I was then able to connect with anyconnect cisco client through SSL VPN Server with split tunnel including 192.168.1.0/24 subnet and was able to ping remote subnet IPs but was not able to resolve network devices by their name(ie. i can ping remote NAS via 192.168.1.7 but not via sharename -> same with accessing them, ie. i can access \\192.168.1.7 but cant access \\sharename)
I was not able to setup Shrewsoft's VPN connector, nor SonicWall, nor any other VPN connector following the old GUI instructions.
My main problem is, that i dont want to use any other vpn connector than device or OS have built in(both Windows and OSX, iOS as well). So possibly across all the devices it would be best to use L2TP/IPSec VPN. I cant use default gw on remote network, because of the traffic. I need to keep the remotely connected clients to the offices to use their VPN connection only for the data directed to the office network.
I have to say as well, that I have set this type of VPNs through several types of services - Windows SBS 2011, Windows Server 2016, Mikrotik routers, Fortigate Fortinet router and I have NEVER experienced these much problems that i have with Cisco RVXXX routers. Sadly, but truly.
Can anybody have working solution for this? Or I can look for another new router?