How to configure the firewall for VPN PPP connections?

[Paul Smith]

On Thu, Feb 19, 2015 at 10:46 PM, Paul Smith <phhs80 at gmail.com> wrote:
>>>
>>> How should one configure the firewall in order to be able to connect
>>> from my machine (Fedora 21) to another machine (MS Windows) via VPN
>>> PPP? Perhaps, after some updates, the possibility of establishing such
>>> a VPN PPP has become blocked by the firewall.
>>
>> What type of VPN?  Both PPTP and IPSec/L2TP use ppp.  Neither should be
>> affected by stock firewall rules if the Fedora machine is initiating the
>> connection.
>>
>> You should check /var/log/audit/audit.log (and/or "setenforce permissive"
>> and test again) for SELinux related errors.  Otherwise, probably
>> /var/log/messages and /var/log/secure will have useful data.
>
> Thanks, Gordon, for your reply.
>
> The type of VPN is PPTP. With the firewall disabled, I can establish a
> VPN connection, but if the firewall is enabled, no VPN connection is
> possible.

The issue may be related to the following:

https://ask.fedoraproject.org/en/question/63759/pptp-connection-fails-after-last-update/?sort=oldest

Paul