;Are you suggesting the following?
;assume eth1 is a better ISP than eth0
ifdown eth0
ifup eth1
ISP on eth1 goes down
automagically detect down ISP on eth1, so
ifdown eth1
ifup eth0
automagically detect ISP back up on eth1, so
ifdown eth0 again
;That isn't gonna fly.
Looks like nate pointed out the right journal article and looks very promising. Will let you know how it goes.
"Source-based routing capabilities are common on high end
networking gear, but they rarely are seen or utilized in server
environments. Linux has excellent but poorly understood
source-based routing support. The whole universe of advanced
Linux routing and traffic shaping is well described at
lartc.org."
ip rules and ip route priority are key.