Important  Changing the C interface IP address significantly impacts the deployment and may require reinstallation of some components. If your appliance is in production and you need to change the C interface IP address, see Changing the C interface IP address. To enable the C interface IP address entry field, place the mouse pointer over the iHelp icon and click "Enable IP field" in the pop-up.

IP address (C interface)	Required. This interface typically requires continual access to the Internet, though some sites use P1 for all communication with the Internet. If you change the IP address of the C interface, the update process may take about 10 minutes. After the IP address is changed, you are redirected to a logon page. Enter your user name and password. The Status > General page will show that the services are starting up. Wait for all services to start.
Subnet mask (C)	Required.
Default gateway (C)	Optional. IP address of the router that allows traffic to be routed outside of the subnet.
Primary DNS (C)	Required. IP address of the domain name server.
Secondary DNS (C)	Optional. Serves as a backup in case the primary DNS is unavailable.
Tertiary DNS (C)	Optional. Serves as a backup in case the primary and secondary DNSes are unavailable.