Morning All,

I have this linux networking problem. Basically what I am trying to do is route a public ip from my webserver which is in colo back into my home network. The setup I have is as follows, On the main DSL line coming into my home there is a BThomehub which dishes out the subnet 192.168.0.0 then behind that I have got a CentOS box which takes the feed from the router into ethernet port 2 (eth1) and then the linux box is setup as a DHCP server and also to masquerade for my subnet in my bedroom which is 192.168.5.0

I am running an openvpn tunnel from my colo server to my home server and have enabled proxyarp on the colo servers main interface. I have then setup a route as follows on the colo server route add -host 87.117.***.30 gw 10.50.0.2 (the ptp ip address for the openvpn connection)

Then I bring up the interface on my home server with the ip address 87.117.***.30 ifconfig tun0:0 87.117.***.30 netmask 255.255.255.255 broadcast 87.117.***.255

Running tcpdump e.g tcpdump -i tun0 icmp shows that there is ICMP traffic arriving on the home linux box but this traffic does not know how to get back to the colo server. How would one go about doing this? Alternatively I would be happy to use a static nat (one to one nat) but I am unsure of the rules I would require on the home gateway to get that data back out through the tunnel rather than my default gateway.

Any help would be much appreciated. My setup is a bit awkward beacuse of the Dual Nat's I have.

Kind Regards

can you post the following:

ifconfig from both vpn endpoints
route -n from both vpn endpoints
sample of relevant tcpdump output from both vpn endpoints so we can see what the source addresses and destination addresses are identified as?
also check /var/log/message for any errors from OpenVPN, it usually will complain if source addresses are bad

of course, please continue to obfuscate at least a portion of any public IP addresses.

I've made a quick diagram of what I gathered your network looks like. The blue line is logical representation of the VPN. (see attachment) This should help others who might want to help get the picture more quickly. Please let me know if there are any relevant errors in the diagram as I had to guess or make up some items to make it somewhat complete (like host IP's etc..).

I'm thinking that static nat at the colo is probably the easiest/best way to get this done.

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