[stunnel-users] behaviour when using 127.0.0.1 in the 'connect' field

Tue Mar 10 12:26:54 CET 2020

Kelly,

Most likely, your OpenVPN server is not listening on (not bound to) your loopback interface. Check your OpenVPN configuration file.

I understand you need to add 
local 127.0.0.1 
to you openvpn.conf

regards,
Jose

> On Mar 10, 2020, at 12:25 AM, Kelly Trinh <kelly at trinhonline.com> wrote:
> 
> Hi all - just want to report a problem I solved recently but wanted to get some insights on what was causing the problem.
> 
> About me - learnt some unix at university (20 years ago) but nothing too serious.  Recently (1 month ago) acquired own domain name and now poking around the cloud computing / VPS thing.
> 
> Project - hand-rolling my own VPN setup on a Ubuntu 18.04 VPS.  OpenVPN is easy since it is a git-clone thing and then just follow the openvpn-install script.  I wanted to add on the Stunnel wrapper because intended to use the VPN in China and apparently their firewall does deep packet inspection and can recognize (and block) openvpn traffic.
> 
> Problem - when I set up my stunnel using 127.0.0.1 as the connect destination; it doesn't seem to work (I can see from openvpn window that things seem to pipe through stunnel but then immediately the connection is terminated).  If I replace the 127.0.0.1 with IP of the box I am using (say for example 1.2.3.4); everything works!  The FQDN is ok as well; as long as I don't use 127.0.0.1
> 
> Specifically the stunnel.conf:
> 
> [OpenVPN]
> Accept = 443  # clients connect through 443 to further avoid potential blocking
> Connect = 127.0.0.1:1194   #<- this line won't work; but if I replace with 1.2.3.4:1194 then it will work!
> 
> Question - My problem is fixed but I am curious if there is any insights on why this is happening given that 1.2.3.4 and 127.0.0.1 are the same machine?
> 
> 
> 
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