Help Needed: I have a Gen3 rev.I Actiontec router, with ethernet connection to ONT. It is running firmware version 40.21.18. I have set up a home PPTP server so I can tunnel in from outside. The server works if I try to connect at home from the same local network as the server is, from both an Android phone and Windows XP machine.
The problem is when I try to connect from outside through the public WAN IP. Worse, even if I am home, and try to connect to the PPTP server using the router's WAN IP wouldn't work, and the PPTP server log shows the same failure (more on this below).
Set-up: FiOS-router Linux box (PPTP server host, on fixed local IP)
FiOS router:
port-forwarding: built-in PPTP rule (TCP Any --> 1723 with GRE) forwarded to the fixed local IP of the Linux box.
GUI setting: Fire wall setting->General, set to Medium or Minimum has no effect.
My own diagnoses:
System logs on the Linux box: The PPTP connection log shows repeated LCP Config requests from the client (Andoid phone or WinXP), and similar LCP Config requests and LCP Config Ack to the Req received, these msg pattern just repeats until timeout.
Packet trace: I used WinDump.exe on WinXP while attempting to connect via the WAN IP of the router (recall that the connection attempt will be successful if I try the local fixed IP of the Linux box). What I can see are repeated LCP Config requests from WinXP to the Linux box (GRE v.1), but no similar GRE packets coming from the Linux box to WinXP, even though the system log on the Linux box says it has send both Req's and Ack's, and also has received LCP Config requests from the Linux box. But the Req's and Ack's the Linux box sent never seems to reach the WinXP.
So my question is: Why aren't the GRE packets reaching the clients (WinXP or Android phone) from the Linux box through the WAN IP, but the other way around is fine? The fact that I can connect if I use the fixed local IP of the Linux box shows that the router itself is not a problem, but somehow router seems to filter GRE packets that goes out from local net (Linux box ==> WinXP or Android) but not the other way around (handled by port-forwarding).
Sorry for the long post, but I want to post as much technical info as possible for someone knowledgeable to help me.
↧