Question:

How do I assign an additional IP Address to an Ethernet (or VLAN) interface in cOS Core?

Answer:

In the WebUI, go to Routing → Your Routing table (e.g <main>) and add a new route that is similar to the following:

Interface=core
Network=ip_wan2
ProxyARP=wan

Note: Even though the property name is “Network”, a single IP address can be assigned to it, as in the example above. An IP range or a network could be assigned instead. A typical usage is assigning another public IP address to a firewall interface. The ProxyARP property is needed so that cOS Core will respond to ARP queries that are expected to arrive at the Wan interface from, for example, an ISP router.

Important: Gratuitous ARPs will not be sent out automatically for these added IP addresses at cOS Core start-up. In case of a hardware change, a manual gratuitous ARP may need to be generated by using the CLI command: “ARP -notify=<ip address> <interface name>”

To configure multiple networks behind the same interface, see: https://kb.clavister.com/324735744

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