poors-man-vpn.sh

#
# in the remote (client) machine
#

sudo ssh -o PermitLocalCommand=yes \
  -o LocalCommand="sudo ifconfig tun1 192.168.123.2 pointopoint 192.168.123.1 netmask 255.255.255.0" \
  -TC -w 1:1 root@ip-of-the-machine-with-the-virtual-servers \
  'ifconfig tun1 192.168.123.1 pointopoint 192.168.123.2 netmask 255.255.255.0; echo tun ready' 

#
# in the machine with the virtual servers to share
#

iptables -I FORWARD -i tun1 -d 192.168.122.0/24 -j ACCEPT

iptables -t nat -I PREROUTING -i tun1 -d 192.168.123.201 -j DNAT --to-destination 192.168.122.201
iptables -t nat -I PREROUTING -i tun1 -d 192.168.123.202 -j DNAT --to-destination 192.168.122.202
(...)