Yes, that is correct. The 7811 is a 5G radio AP, and it's Ethernet connects to your
DSL/Cable modem with Internet access.
Pre-configure with a static IP address on your PC/laptop, at http://192.168.2.1 with
login of super / sp-admin. Use the Configuration::Wireless page to configure your
WLANs. A Video WLAN is bridged to the WAN/Internet connection (and you may
not get a second IP from your ISP), while a local Data WLAN will connect your wifi
clients to your Local Network (where you configure DHCP scope size).
Under Configuration::Internet, leave the Connection Type as DHCP, to get the AP
address from the DSL/Cable modem.