1.FAQ
1.24 Is it possible to establish a vtun link from a client behind NAT or a firewall?
Yes it is, but you need to use TCP protocol.
1.22 Where can I get more information about VTun ?
VTun package contains:
Manual page for vtund.
Manual page for configuration file.
Fully documented config file.
Several README files.
1.16 Why ZLIB compression does not work with UDP protocol ?
UDP doesn't not provide reliable transport, and some frames could be
lost on unreliable links. VTun does not have any retransmission or
recovery algorithm for the lost UDP frames, because retransmission will
be handled by Upper layers.
You should use LZO compression with UDP protocol.
（
- Challenge based authentication.
No clear text passwords. 沒有明文密碼
）
1.17 Why PPP tunnel is unstable over UDP ?
Explanation is the same as with above case. Use TCP for PPP tunnels or
use TUN instead of PPP, since tun device is completely the same with
ppp device for the kernel.
1.17 Why PPP tunnel is unstable over UDP ?
Explanation is the same as with above case. Use TCP for PPP tunnels or
use TUN instead of PPP, since tun device is completely the same with
ppp device for the kernel.
1.12 What do I need to run VTun ?
You should install and configure VTun package and read documentation.
Usually you'll need:
Universal TUN/TAP device driver (http://vtun.sourceforge.net/tun)
PPP driver and pppd.
1.10 Does VTun server support multiple clients ?
Sure. Number of the clients is limited only by the capabilities of
your machine.
1.11 How many tunnels can VTun handle ?
Number of the tunnels is limited only by the capabilities of your
machine.
1.8 Does VTun support PPTP, L2TP, IPsec ?
VTun uses it's own simple and efficient protocol with TCP or UDP.
It doesn't support PPTP, L2TP, IPsec.
附：vtun features
1、Tunnel Types
- IP tunnel (tun).
Supports point-to-point IP tunnel. - Ethernet tunnel (ether).
Supports all protocols that work over Ethernet: IP,IPX,Appletalk,Bridge,... - Serial tunnel (tty).
Supports all protocols that work over serial lines: PPP,SLIP,... - Pipe tunnel (pipe).
Supports all programs that works over Unix pipes.
從上述Typse可以看出隧道類型的劃分標準主要是所支持的協議類型。
2、Protocols
- VTun protocol over TCP.
Allows to establish tunnels behind firewalls. Very reliable. - VTun protocol over UDP.
Fast and efficient protocol with small tunneling overhead.
3、Compression
- Deflate (zlib).
Very efficient compression. Supported for TCP only. - LZO (lzo).
Super fast compression. Supported for UDP and TCP.
4、Encryption
- Challenge based authentication.
No clear text passwords. - BlowFish 128 bits key.
Fast efficient encryption with 128 bits MD5 hash keys.
5、Traffic Shaping
- Platform Independent Traffic Shaper.
Allows to limit inbound and outbound speed of the tunnels.
6、General
VTun is the easiest way to create Virtual Tunnels over TCP/IP networks. It support various tunnel types and provides many useful features:
- Encryption
- Compression
- Traffic shaping
VTun is easily and highly configurable. It can be used for various network tasks:
- ***
- Mobile IP
- etc