Rob Townley wrote:
>
>
> Routes only work when you can reach the next hop. That is, if you
> try to add a route through an interface that is not up, the command
> will fail and the route will not be added. If you want a route to
> be added when an interface comes up, there is already a place to do
> that. However, as others have pointed out you shouldn't expect
> multiple concurrent default routes to do something useful - but if
> you have multiple interfaces you can configure them both to add
> default routes and bring only one up at a time.
>
>
> ;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.
The 'right' way to use multiple ISP's is to configure BGP routing with
all of them so you learn the best routes to any destination. However
that is non-trivial to set up and maintain and requires a large block of
public IP addresses.
I haven't read the whole thread here - what problem are you trying to solve?
--
Les Mikesell
lesmikesell at gmail.com