[pptp-server] MS clients cannot connect to PoPToP through ISP, because of filtered GRE packet

DaeSooChoi dschoi at superstar.co.kr
Wed Feb 14 21:55:09 CST 2001


Hi 
I am appreciated NewGroup members' help.
Thanks to members faver. I find out that ISP filters pptp packets (protocol# 47 GRE) pass from remote user(MS clients) to PoPToP Server.

> I have a pptp-server running that has no problems with MS windows clients over local LAN connecting, 
> but when my MS windows client attempts to connect to pptp-server through dialing-up isp. 
> 
>               MS pptp client <------------local lan---------------> Linux PoPToP server  (connection OK)
> (problem) MS pptt client <---dialing---> (through)ISP <------------internet------------> Linux PoPToP server ( connected (like below message)but disconnected immediately)
   (casue)                                               filterd protocol #47(pptp packet)

Our ISP(located in SOUTH KOREA) filters GRE packets.
I would like to know how GRE packets can pass through ISP.
and...also Do you know that other country ISPs filter out GRE packets (except tcp/udp/icmp/...)

Any help appreciated.




More information about the pptp-server mailing list