[pptp-server] pptp through firewall

[Cowles, Steve]

> 
> Okay, here goes... Sorry about the confusion, I 
> misinterpreted "remote end" as "client."
> 
> 1) Cut/Paste of /var/log/messages for pptp connection from remote.
> Jul 19 12:11:29 thing pppd[17845]: pppd 2.3.11 started by root, uid 0
> Jul 19 12:11:29 thing pppd[17845]: Using interface ppp0
> Jul 19 12:11:29 thing pppd[17845]: Connect: ppp0 <--> /dev/pts/0
> Jul 19 12:11:32 thing pppd[17845]: CHAP peer authentication 
> succeeded for vpnuser
> Jul 19 12:11:36 thing pppd[17845]: found interface eth0 for proxy arp
> Jul 19 12:11:36 thing pppd[17845]: local  IP address 192.168.200.240
> Jul 19 12:11:36 thing pppd[17845]: remote IP address 192.168.200.242
> 
> 2) Cut/Paste of "ifconfig ppp0" after connection is brought up.
> ppp0      Link encap:Point-to-Point Protocol
>           inet addr:192.168.200.240  P-t-P:192.168.200.242
>           Mask:255.255.255.255
>           UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1500  Metric:1
>           RX packets:72 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:22 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:10
> 
> 
> 3) Cut/Paste of "netstat -rn"
> Kernel IP routing table
> Destination     Gateway   Genmask         Flags   MSS 
> Window  irtt
> Iface
> 192.168.200.242 0.0.0.0   255.255.255.255 UH      0 0 0 ppp0
> 192.168.200.0   0.0.0.0   255.255.255.0   U       0 0 0 eth0
> 0.0.0.0         192.168.200.1   0.0.0.0   UG      0 0 0 eth0

The above looks good. 

Are you sure you have ip_forwarding enabled on the PPTP server???

To verify type: cat /proc/sys/net/ipv4/ip_forward

If ip_forwarding is enabled, the above should print out "1", it not it
should print out "0"

To Enable/test ip_forwarding (temporarily), will not live thru a reboot:
echo "1" >/proc/sys/net/ipv4/ip_forward

Based on your linux disto, you can enable ip_forwarding (permanently) thru
gui's or edit either:
/etc/sysconfig/network
  or
/etc/sysctl.conf

and change the ip_frowarding variable to "1"

Steve Cowles