Hello, i am trying to have eth0 connected to eth1 on the same machine with a loopback cable. I have eth0 as 2.2.2.1 and eth1 as 2.2.2.2 with netmask 255.255.255.0 and the right Bcast 2.2.2.255 . I tried to ping -I eth0 2.2.2.2 and ping -I eth1 2.2.2.1. My issue is that even when the loopback cable is not plugged the ping still succeed( as if it is an internal ping). How can I force an external ping where I make sure the packets are going through the connected cable? ( I know I can have a router and both ethernets connected to it, but I am avoiding to use anything besides a simple cat 5 cable). Thanks.