I have two network interfaces eth0 and eth1 and I just wanna know how get the "eth1" as default route automatically if the "eth0" goes down?
What you want is called
The ifcfg-bonding manpage (& references) may also be of help, and is probably more up-to-date than any tutorials you'd find by googling..
You can use the metric argument to
This is the "old school" way of doing things.
You may also be interested to learn about iproute2:
For more details, see: