I have two Internet lines with Sonicwall firewalls. I need one line to provide connectivity to a few servers, and the other to serve as a backup in case the primary fails. I don't think we need any type of load balancing, just need the backup redundant line to kick in when the first fails. Would I be able to accomplish this with a couple Cisco switches I have lying around? Maybe implement some kind of trunking? How would I do this?
A better way to do it would be running VRRP on the firewalls. This way, you would not need any special trunking on switches, etc. I am assuming that the Internet connections are going in separate firewalls. This way, you would be able to have a virtual IP Address, which would be owned by the primary Firewall. In case the primary firewall fails, the secondary firewall would take over, and start servicing the same virtual IP Address. For information on how to implement this, please refer to the documentation. If these firewalls don't support VRRP, then they must be having some proprietary mechanism for fail over.