This seems to be a very basic question.
I have 3 subnets (say, 10.1.x.x, 11.1.x.x, 12.1.x.x). I'd like to connect allow communication between the subnets, and I'm looking at purchasing the Cisco 1812 router to do so.
To connect the subnets, I understand that I'd need 3 network interfaces, with 3 different IP addresses (say 10.1.1.1, 220.127.116.11, and 18.104.22.168). Could I do this using 2 WAN ports (for the 10.1.x.x and 11.1.x.x subnets) and the 8-port integrated switch for the 12.1.x.x subnet?
A CISCO pre-sales support employee told me that this isn't how you use the WAN ports, and that I'd configure the switch ports for this. I don't believe his response to be correct.
Thank you in advance.