Adding a Secondary WAN Subnet to Sonicwall and a Cisco

Example:

Current WAN IP range:   100.100.100.0/24
Sonicwall WAN IP:           100.100.100.100
Cisco Router:                   100.100.100.1
New WAN IP range:        101.101.101.0/27

You can add a static ARP entry on the Sonicwall but there is an easier method. Simply set a static route on your Cisco router.

# ip route 101.101.101.0 255.255.255.224 100.100.100.100

Then on the Sonicwall, just set up the address objects, NAT policies and any firewall rules that you need.