Is it possible to add two IP addresses on one NIC?

Question

Computer networks

Good evening!
There is a router on DD-WRT (address 192.168.1.1), which I study and experiment all the time. In addition, to access the Internet (ADSL with a limited tariff plan), I always prescribe the IP addresses of the provider, the modem is configured in Bridge mode.
Is it possible to make both DD-WRT and ISP addresses coexist together? Without manual intervention in the settings?
Thank you!

Answer 1

You can add a Secondary ip address. But that won't help you much. It will be necessary to think over the switching logic.