I just set up a pptp server on Debian Linux and I can connect to the server from my iPhone when in the same network as the PPTP server. But when I leave my office network, I can't connect to the vpn. On the router, I have forwarded port 1723 for PPTP but still no luck.


  • You are using your routers hostname and/or IP Address when you are on the outside right? – Tim Jan 3 '12 at 19:46
  • Yes I am using my external ip to connect because I have static ip. – David Jan 3 '12 at 20:05

PPTP uses tcp/1723 and GRE (ip protocol 47).

How you permit GRE traffic depends on the router. Keep in mind though that you typically can only have a single PPTP session that will work through a NAT.

  • I don't get how to enable gre ip 47 on a Linksys router. I do have "VPN passthru" for pptp enabled if that's what you are referring to. – David Jan 3 '12 at 20:04

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