Hi,

Actually we are running in troubles with our upstream. For any reason (only god knows) the port for pptp connections (tcp, 1723?) are actually blocked by our provider.
This is a big trouble for us, because we are using this tunnels for our monitoring. As far as I can see, there is no way, to change the port, which is used by the pptp client & server. The helpdesk of our provider states: "no, we don't change anything" (I expected this answer )

Anyway I'm searching for a solution now ~ if you have a hint for me, i would be realy happy. A completly different way to solve this problem is also possible (but I haven't seen anything in mikrotik, which could replace a pptp-tunnel).

Best regards & thanks in advance,
soft*seeing a long night with much work*down

We use the same solution for monitoring and it works wonderfully.
I think that an ISP has no interest to bloc this port, check the Firewall configuration on your MT router or on your Internet equipement (ADSL router )
good luck

Hi MarTux,

Thanks for your reply!

Anyway it isn't realy a simple configuration issue. We are using ~50 pptp-connections and they worked fine for the past 2 years. The intention of this port blocking is to avoid voip (which is not allowed here). Since the upstream can't see which kind of traffic is going into this pptp connections, he simply blocks them (and there is no realy way to talk with them - live with it, or don't have internet... very simple, if there is only one provider in this country and you are not allowed to buy traffic anywhere else).

So you see, I will have to search for a solution to change the ports (I believe, that they don't analyze the traffic - we had the same issues with SMTP here - as for this we simply changed our postfix to also listen on port 26).

Best regards,
softdown1

do they also block GRE ? Maybe you can use IPIP tunnels or other. Also you could try to redirect port 1724 to 1723 using nat redirect ? Never tried.

Forget about PPTP and use L2TP - configuration exately the same only it runs over UDP port 1701