I'm trying to connect a Linux (Ubuntu 10.04 LST) server to a VPN server via the PPTP client to an VPN server. I configured the PPTP client as said in the documentation. The connection is correctly added as an interface, but somehow the connection dose not work. ping -I ppp0 google.com
dose not return anything and traceroute -i ppp0
only shows the first hop, and then displays nothing. Any ideas of what is going wrong? Incorrect routing configuration?
ifconfig
output for the configured interface:
ppp0 Link encap:Point-to-Point Protocol
inet addr:xx.x.xxx.xxx P-t-P:10.0.0.1 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1496 Metric:1
RX packets:415 errors:0 dropped:0 overruns:0 frame:0
TX packets:468 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:31428 (31.4 KB) TX bytes:32394 (32.3 KB)
route
output
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
xx.x.x.1 * 255.255.255.255 UH 0 0 0 ppp0
xx.xxx.xxx.xx sp.ip 255.255.255.255 UGH 0 0 0 eth1
192.168.3.0 * 255.255.255.0 U 0 0 0 eth2
192.168.2.0 * 255.255.255.0 U 0 0 0 eth1
default sp.ip 0.0.0.0 UG 100 0 0 eth1
Best Answer
You need to configure NAT IP-Masquerading with
iptables
on the remote server. Otherwise your client server can't access the internet via the vpn with a single IP address of the remote server.in a nut shell:
these two lines show how IP-Masquerading could be setup.
if you are not familiar with
iptables
, there are plenty tutorials for it on the internet.FYI, tldp hosts a rather detailed instruction on setting up ip-masquerading. http://tldp.org/HOWTO/html_single/Masquerading-Simple-HOWTO/