Subject: Networking setup question
From: Matt Paine <matt@mattsoftware.com>
Date: Mon, 16 Mar 2009 14:54:25 +1000

Hi Guys.

I am trying to achieve a private network behind my public internet. Can 
anyone let me know where I am going wrong (or of its even possible to do 
this??).


Interfaces on the host:
* eth0 (public internet, visible to the world)


I have a PPTP server on the host which assigns 10.0.1.x addresses. I 
want the clients to be able to communicate with the vserver guest.

Guest is setup with interface 0...
ip = 10.0.0.1
mask = 255.0.0.0
dev = eth0
name=vps


All the communication appears to be working fine, until the guest tries 
to resolve a DNS entry. On closer inspection it doesn't seem that that 
guest can ping any ip outside of the host....

bash-3.2# ping 10.0.0.1
PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=0.041 ms
64 bytes from 10.0.0.1: icmp_seq=2 ttl=64 time=0.022 ms
64 bytes from 10.0.0.1: icmp_seq=3 ttl=64 time=0.024 ms

bash-3.2# ping 121.50.218.162
PING 121.50.218.162 (121.50.218.162) 56(84) bytes of data.
64 bytes from 121.50.218.162: icmp_seq=1 ttl=64 time=0.037 ms
64 bytes from 121.50.218.162: icmp_seq=2 ttl=64 time=0.017 ms

bash-3.2# ping 74.50.3.85
PING 74.50.3.85 (74.50.3.85) 56(84) bytes of data.



bash-3.2# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use 
Iface
10.0.1.1        0.0.0.0         255.255.255.255 UH    0      0        0 *
121.50.218.160  0.0.0.0         255.255.255.248 U     0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     0      0        0 eth0
10.0.0.0        0.0.0.0         255.0.0.0       U     0      0        0 eth0
0.0.0.0         121.50.218.161  0.0.0.0         UG    0      0        0 eth0


Any hints would be appreciated. (of course if you require any more 
information let me know what you require and I'll provide :)


Thankyou
Matt.
mattsoftware.com