Virtual Tunnel

Virtual Tunnel(VTun) is similar to Softether,
even more powerful for Linux or FreeBSD.
To build VTun, needs following rpms
liblzo1
liblzo1-devel
bison or byacc (byacc build failed in my case, so I install bison rpm)
Working example:
Server config /usr/local/etc/vtund.conf

default {
  type tun;
  proto udp;
  compress lzo:1;
  keepalive yes;
}

s2 {
  passwd abcd;
  up {
   ifconfig "%% 10.10.0.1 pointopoint 10.10.0.2";
   route "add -net 10.10.1.0 netmask 255.255.255.0 gw 10.10.0.2";
   program /sbin/arp "-sD 10.10.0.2 eth0 pub";
  };
}

Client config /usr/local/etc/vtund.conf

default {
  type tun;
  proto udp;
  compress lzo:1;
  keepalive yes;
}

s2 {
  passwd abcd;
  up {
   ifconfig "%% 10.10.0.2 pointopoint 10.10.0.1";
   route "add -net 10.10.0.0 netmask 255.255.255.0 gw 10.10.0.1";
  };
}

Before run vtund, both client and server needs to load tun module (modprobe tun), then
Server run vtund -s
Client run vtund s2 140.117.53.147
(140.117.53.147 is server IP)

Result:
Server
tun0 Link encap:Point-to-Point Protocol
   inet addr:10.10.0.1 P-t-P:10.10.0.2 Mask:255.255.255.255
   UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
   RX packets:15 errors:0 dropped:0 overruns:0 frame:0
   TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
   collisions:0 txqueuelen:10
   RX bytes:1260 (1.2 Kb) TX bytes:672 (672.0 b)

Client
tun0 Link encap:Point-to-Point Protocol
   inet addr:10.10.0.2 P-t-P:10.10.0.1 Mask:255.255.255.255
   UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
   RX packets:8 errors:0 dropped:0 overruns:0 frame:0
   TX packets:15 errors:0 dropped:0 overruns:0 carrier:0
   collisions:0 txqueuelen:10
   RX bytes:672 (672.0 b) TX bytes:1260 (1.2 Kb)

ref. Softether