Hi,

Thanks to a link in the other PPTP thread currently running on this list, I 
found this page in the docs :

http://doc.pfsense.org/index.php/Connect_to_a_remote_PPTP_server_when_you_have_the_pfSense_PPTP_server_enabled

As stated there it is not possible to NAT PPTP and GRE traffic via the 
non-default WAN IP without installing an extra package, or without knowing 
beforehand all the PPTP servers your users will try to connect to in the future.

However, I would like to mention that in the past few years I have been 
successfully running inbound and outgoing PPTP connections on pfsense 1.2.x, 
even in situations with +500 users, by just 'turning the solution around'.
Of course it also only works when you have more than one WAN IP available, 
since it uses advanced outbound NAT.

In stead of trying to NAT specific traffic like PPTP and GRE traffic to a VIP 
address to solve this issue, I just set up advanced outbound NAT to NAT ALL 
traffic from LAN clients through a VIP. The firewall WAN address therefore 
stays free and is used only for VPN connections (and a few internal services on 
pfsense)
This way, pf can very easily keep inbound PPTP and GRE connections to its own 
PPTP server seperated from the PPTP and GRE traffic from local LAN clients. (Of 
course you are still limited to one simultaneous outgoing connection to the 
same PPTP server, because of the way PPTP works)

Details:
First you create a VIP on your WAN interface. This VIP is not to be used in 1:1 
NAT mappings or port forwards, it should be left free for the advanced outbound 
NAT.

In the advanced outbound NAT page you disable the automatic setting and add a 
rule on the WAN interface for EVERY local subnet you have that should be able 
to reach the internet, stating the local subnet as the source and ANY as the 
destination, setting the outgoing address to the beforementioned VIP on the WAN 
interface.

After applying, you may which to clear the state table to see the changes take 
effect. 


This way, all your clients use the VIP address for their internet traffic, and 
you don't have to set up NAT rules again and again for every PPTP server on the 
internet that your users are trying to reach. And you don't have to install a 
package for a simple NAT issue.

Just thought writing it down, it might be usefull to someone some day.

Regards,

Hans

Reply via email to