Re: [Openvpn-users] Can OpenVPN be used as "pure" SSL VPN?

[Jon Bendtsen <jon.bendtsen@xxxxxxxxxx>]

Den 3. jun 2004, kl. 23:06, skrev Small, Jim:

> I am looking for an Open Source "pure" SSL VPN.  By "pure", I mean that
> everything/all negotiation occurs over port 443/TCP.  When I looked 
> through
> the documentation, it looked like OpenVPN requires an open UDP port.  
> This
> is not possible for my situation.  I have a vendor that only allows 
> ports
> 80/TCP and 443/TCP, no exceptions.  Is it possible to use OpenVPN as 
> an SSL
> VPN with only port 443/TCP open?

yes

http://openvpn.sourceforge.net/man.html


--proto p
    Use protocol p for communicating with remote host. p can be udp, 
tcp-client, or tcp-server.

    The default protocol is udp when --proto is not specified.

    For UDP operation, --proto udp should be specified on both peers.

    For TCP operation, one peer must use --proto tcp-server and the 
other must use --proto tcp-client. A peer started with tcp-server will 
wait indefinitely for an incoming connection. A peer started with 
tcp-client will attempt to connect, and if that fails, will sleep for 5 
seconds (adjustable via the --connect-retry option) and try again. Both 
TCP client and server will simulate a SIGUSR1 restart signal if either 
side resets the connection.

    OpenVPN is designed to operate optimally over UDP, but TCP 
capability is provided for situations where UDP cannot be used. In 
comparison with UDP, TCP will usually be somewhat less efficient and 
less robust when used over unreliable or congested networks.

    This article outlines some of problems with tunneling IP over TCP:

    http://sites.inka.de/sites/bigred/devel/tcp-tcp.html

    There are certain cases, however, where using TCP may be 
advantageous from a security and robustness perspective, such as 
tunneling non-IP or application-level UDP protocols, or tunneling 
protocols which don't possess a built-in reliability layer.



--port port
    TCP/UDP port number for both local and remote.
--lport port
    TCP/UDP port number for local (default=5000).
--rport port
    TCP/UDP port number for remote (default=5000).


____________________________________________
Openvpn-users mailing list
Openvpn-users@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/openvpn-users