ip takeover.

[Michael Robinson]

I have been looking into advanced routing to automate
the raising and lowering of a substitute gateway to the 
Internet using the sole ISP assigned global ip address
I've got to work with.  The dhcp server says that the
gateway is at 192.168.1.12, the original router.  How do
I provide information about the substitute without aliasing
the original local address on the substitute box potentially
making it hard to bring the original back up without manual
intervention on the sub?  When the original is up it is the
gateway, up means that you are a working gateway or 
should I simplify this and say that up means your external
card is up.  I want to favor the original box when it wants to
come up in my scheme.  I wouldn't assume that the standard
detection method is whether or not gateway is passing packets.

If I don't have to alias on the sub for the local address and I don't
use a switch to plug in both external cards to the bridge box
simultaneously, I guess I can have both external cards up with
the same ip address and just manually plug the line from the 
bridge to the currently used gateway.  Otherwise, one external
card needs to go down when the other comes up or I need to 
buy more global ip addresses, which I want to avoid.  If I have
to alias the 192.168.1.12 address I have to release the alias 
before the original comes back where I'm wanting to automate this.  

This is some challenge :-)

   -- Michael C. Robinson