We have 2 ISP and we've tried configuring backup between them.
we used :
ip route 0.0.0.0 0.0.0.0 gw_isp1
ip route 0.0.0.0 0.0.0.0 gw_isp2 10.
we tested it by shuting down the interface or unplugging the cable.It works fine.
The problem is that we have an ethernet port connected to isp1 and when internet goes down, the interface is still up.
How should we really configure the backup ?