In the event that the internet connection is DOWN (box is fine just the cable modem is down) how do I set things up so I can take advantage of the second internet connection?

there are more ideal [and complex] ways of setting up the connections so you only use one firewall - maybe using the second as a failover - but assuming you want to keep your infrastructure the same:

create a second routing table one the cable modem firewall, with a default route of the other firewall.

(assuming the other firewall is 10.10.10.2 and the internal NIC is eth1)

# echo 2 >> /etc/iproute2/rt_tables # ip rule add fwmark 3 table 2 # ip route add default via 10.10.10.2 dev eth1 table 2

write a simple bash script that pings the cable modem's gateway. on failure, after a predetermined amount of time, add an "iptables" rule such as the following to use the second routing table:

(assuming 10.10.10.0/24 is your internal LAN) # iptables -t mangle -A PREROUTING -s 10.10.10.0/24 -j MARK --set-mark 3

You can extend your BASH script to remove the IPTABLES rule once it re-establishes contact with your cable modem's gateway.

it's not an elegant solution, but it's a simple one.

-ken

Thanks for any tips.

Jerry