I'm stumbling on a problem that requires your advice.

Keywords : networking, route, openVPN

Problem : I have a local network with several physical servers and VMs. These machines have ip's in the range 10.10.x.x. I can access these machines from the Internet with the help of openVPN. These machines can :

• access each other within the local 10.10.x.x subnet
• access the Internet via the VPN
• can themselves be accessed (via SSH) from the Internet via the VPN.

There is one machine however that behaves strangely and I don't know why. I can SSH into this machine from anywhere via SSH and I can also PING it from anywhere (including the Internet). However from this machine (i.e. when logged into it) I cannot access the Internet or ping machines outside the local network. In other words it will not go beyond the VPN. My question is why? Here are some technical details:

The machine's Network Config (running Debian 6.0.3):

• allow-hotplug eth0
• iface eth0 inet static
• address 10.10.10.200
• netmask 255.255.0.0
• network 10.10.10.0
• broadcast 10.10.10.255
• gateway 10.10.10.200

The machine's Routing :

• Destination Gateway Genmask Flags MSS Window irtt Iface
• 127.0.0.1 0.0.0.0 255.255.255.255 UH 0 0 0 lo
• 10.10.0.0 10.10.10.250 255.255.0.0 UG 0 0 0 eth0
• 10.10.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
• 0.0.0.0 10.10.10.250 0.0.0.0 UG 0 0 0 eth0
• 0.0.0.0 10.10.10.200 0.0.0.0 UG 0 0 0 eth0

The VPN's Network Config (running Debian 6.0.3):

• # This is the local network interface
• auto eth1
• allow-hotplug eth1
• iface eth1 inet static
• address 10.10.10.250
• netmask 255.255.0.0
• broadcast 10.10.10.255
• gateway 10.10.10.250

The VPN's routing table

• Destination Gateway Genmask Flags MSS Window irtt Iface
• 10.10.0.0 0.0.0.0 255.255.255.0 U 0 0 0 tun0
• private 0.0.0.0 255.255.255.0 U 0 0 0 eth0
• 10.10.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1
• 0.0.0.0 10.10.10.250 0.0.0.0 UG 0 0 0 eth1

• 0.0.0.0 private 0.0.0.0 UG 0 0 0 eth0

• net.ipv4.ip_forward = 1 on both machines.

• there are no iptables set anywhere.

Thanks in advance for any feedback.