View Full Version : [ubuntu] PPTP server setup and routing

March 4th, 2009, 11:52 AM
Trying to get my PPTPServer running i got some issues, which are hard to figure out.

My setup is like this:

--- dsl-p4 -- vpn eth1 -- PPTPserver -- lan eth0 -- dsl-p1---

eth0 = (gateway
eth1 = (gateway this subnet is in DMZ
dsl-p1 = router port 1 configured for local lan (
dsl-p4 = router port 2 configured for vpn connections (
VPN clients will have ipadresses in the range

The routing is default like this on the server.

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface * UH 0 0 0 ppp0 * U 0 0 0 eth0 * U 0 0 0 eth1
default dsldevice.lan UG 100 0 0 eth1
default dsldevice.lan UG 100 0 0 eth0

1) There seems to be somwething wrong with routing, since i cant make connections to internet from the server itself over eth0. Lan connection over eth0 is no problem en works fine. How should the network be configured? Should every nic has its own gateway configured? Bringing down eth1 results in a good connection to internet over eth0.
My nic setup:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
# LAN side NIC of POPTOP Server
auto eth0
iface eth0 inet static

# WAN side NIC of POPTOP Server
auto eth1
iface eth1 inet static

Do i need for both nics a gateway?
It seems that if i don't configure the gateway for eth1, it doesn't accept connections.