On Wednesday 23 October 2002 7:26 pm, Stewart Thompson wrote: > HI Harish: > > Perhaps I should have asked for more facts. I assumed, > perhaps incorrectly, that you wanted to forward the DNS request > across the Internet It is my understanding that your IP fell within > the private Class B IP range of 172.16.0.0 - 172.31.255.255. > It is also my understanding that routers on the Internet drop IP's > that fall into established private IP ranges. If I am wrong on this > point, someone please correct me. You are correct in your assumption. Routers have for a long time dropped packets with private destination addresses (if for no other reason than there's nowhere to send them), and it is very common nowadays for routers also to drop packets with private source addresses, so they don't even reach their (perfectly legally addressed) destination. However, since Harish says he has a CheckPoint FW-1 between his Linux box and the Internet, doing NAT for him, it will allow originally 172.16.x.y addressed packets to get out and the replies to come back again. Hence the desire to send DNS requests from a specific private IP address seems reasonable in this case. I hope that my earlier response, suggesting the use of the POSTROUTING chain, is helpful in achieving this. Antony. -- Behind the counter a boy with a shaven head stared vacantly into space, a dozen spikes of microsoft protruding from the socket behind his ear. - William Gibson, Neuromancer (1984)
