I have a question regarding the IPIP on linux. Following is the current situation we have. Diagram below. Linux A Linux B ________ _______ | | | |--- Internet ----| |--private---| |--- Client |______| network |_____|--- machines using public IP Linux A has two interfaces, one is ethernet connected to internet, and the other interface is token ring adapter. Linux B has token ring adapter connected to Linux A, and Linux B has three ethernet interfaces and clients will connect to Linux B to use internet. >From above, it isn't that bad to give our clients internet access through our network, but here comes the problems. The problem we're facing is we have huge subnet (even though main idea is the same as Box A & Box B) and we are using public IP addresses as our private network's ip addresses. For this reason, we are trying to hide our network from the clients. Yes there maybe some case that the client can actually try to access the host that has the duplicated ip address as one of our machine does. The way we try to solve this is by using the tunneling between the linux A and linux B. My question is if it's possible to setup the tunnel between the interface that connected to internet on Linux A and the interfaces that connected to client machines on Linux B. I can make tunnel between the interfaces that connected to the internal network on Linux A and Linux B, but I couldn't quite make above senario working. At this point, I'm not even sure if IPIP supports above configuration. Some reason, I can't move or introduce any other machines. If you have any suggestion or how the routing table should look like, feel free to list here please. Thanks in advance. __________________________________ Do you Yahoo!? The New Yahoo! Shopping - with improved product search http://shopping.yahoo.com