On Mon, Aug 31, 2009 at 3:35 PM, Ashish Verma<ashishverma1...@gmail.com> wrote: > Hi, > > I have two systems, 1 server and the other client. > The server has 2 interfaces, 1 in 172 network and the other in 192 network. > In the client I have configured the server as the default gateway. There is > only one interface on the client configured wiht 172 network. > > Now, whether or not I set the net.ipv4.ip_forward to "1", I am able to ping > the 192 interface from the client on 172 network. *Is this expected > behavior?* There are no iptables or anything of that sort configured. >
I will clear the confusion with the net.ipv4.ip_forward sysctl setting. Routers alone do IP forwarding. You need not run a routing daemon for that. You can have a simple static route table and forward packets between two networks. And send the remaining packets to the default router. Routing is very different from forwarding. Routing involves running a heavy duty daemon like BGP or OSPF. And it involves discovering routes on the Internet and keeping it upto date. Routing algorithms and protocols are very complex. A router is defined as a node with at least 2 interfaces. Otherwise running these daemons make no sense. Obviously routers forward packets between different networks of course. Whereas forwarding is different. You can setup many networks at a home or office LAN and forward packets based on static routes and simple route lookups. Now to answer your question after all this digression, you don't need this sysctl for forwarding/routing for ping to work. You are barking up the wrong tree. Normally it is very rare that you set this sysctl. You do it if you are a firewall or a proxy or if you are running squid. -Girish -- Gayatri Hitech web: http://gayatri-hitech.com SpamCheetah Spam filter: http://spam-cheetah.com _______________________________________________ To unsubscribe, email ilugc-requ...@ae.iitm.ac.in with "unsubscribe <password> <address>" in the subject or body of the message. http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
