How to set up a vpn connection in a virtual machine?

Question

VPN

Hello, I have a server with lubuntu, I installed virtualbox on it, created a virtual machine with windows 7. And now I'm trying to connect to my vpn from the VM (I have it on my PPTP router). Can't connect in any way, error 619 crashes "cannot connect to the remote computer, so the connection port is closed." On my own PC (windows 7) I can easily connect to vpn, so I think maybe something is interfering with lubuntu?
PS I checked on my VDS with ubuntu without a VM, and connected directly with ubuntu without any problems

Answer 1

The scheme as I understand it is this:
windows7 --> lubuntu --> router(pptp)
Is routing enabled on lubuntu? IPv4?
Check if forward is allowed in iptables between interfaces internal where the virtual machine is and external where the router is. Is there any blocking on ports, protocols and target addresses. If you are not using NAT
on lubuntu then the router needs to know where to send the response!!! That is, the router should have routing to the network where the virtual machine is located through the external interface of your lubuntu windows7 check ping to the lubuntu interface which is closer to the interface which is further then check ping to the router Of course, the router and lubuntu must respond to ping (ICMP)
On lubunt, you can watch the ping traffic

apt-get install tcpdump
# tcpdump -i any proto ICMP