Using runlevels to demote a network king to a mere baron
Using runlevels to demote a network king to a mere baron I have put enough services onto my server that it has become a single-point of failure. Its a router, a DSL modem, backup storage, and has network-shared drive, plus a few other cool things. The key point of failure is the combination of Modem + Router. The PCI DSL card requires a custom driver, and sometimes after a system upgrade it needs to be reinstalled. The details of the wanrouter driver are here. What I need is a failover mode: If the DSL fails to work, I want to use my old external modem and router. So I still want the system to run, but as a dchp-client server instead of a router. Lets use some startup logic and runlevels to define two roles for the server: Network King routing over DSL, and faithful Baron merely connecting over wi-fi to the Linksys. And a bit of connective tissue so the machine automagically boots into the correct role, plus can be switched manually. Internet <------+ Network King +-----> LAN Int...