eth0 & ppp0 revisited

[John Bagdanoff <bagdanof@home.com>]

I've been experimenting getting ppp running as a backup when my cable
modem connection goes belly up for whatever reason.
I disable eth0 with: ifdown eth0.
Then I pon
& later I poff
I then do a: ifup eth0
Now I cannot access the internet through my cable modem (connected to
eth0).
My original routing table before ifdown is:

Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface
192.168.1.0     *               255.255.255.0   U     0      0        0
eth1
localnet        *               255.255.252.0   U     0      0        0
eth0
default         bb1-fe0-0-0.pot 0.0.0.0         UG    0      0        0
eth0 

After the ifup my table is:

Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface
192.168.1.0     *               255.255.255.0   U     0      0        0
eth1
localnet        *               255.255.252.0   U     0      0        0
eth0
default         24.7.136.1      0.0.0.0         UG    0      0        0
eth0


Now, if I run pon/poff again, my default gateway for eth0 reverts back
to: 

default         bb1-fe0-0-0.pot 0.0.0.0         UG    0      0        0
eth0 



Now that I've invented the hard way to fix this, what's the easy way?

John