Two networks on the same computer - Ubuntu

Question

I am hoping to get some advice on how to achieve the following:

I have a video encoding device that essentially acts like an IP camera, in that you would normally plug it into an existing network over ethernet and access it through a web browser by entering its IP address on that network.

I want to connect this device to one of two ethernet ports on a computer running Ubuntu and have it accessible only by that computer on it's own network (with the encoder as the only device on the network besides the computer), then have that computer connected to another LAN through one of the other ethernet ports.

The purpose is to be able to have the computer stream the video feed to an AWS Kinesis account through the LAN, but not have the video encoder accessible directly on the same LAN, hopefully this will serve as a basic visualisation of what I have in mind.

[Video encoder]---(ethernet cable to Eth0)---[Ubuntu Computer]---(ethernet cable to Eth1)---[LAN router]

I apologise in advance for having probably under-described the scenario and am happy to elaborate more if needed. This would be a consequence of limited experience in both Linux systems and networking, neither of which I have had to work with much before, but am trying to learn through projects like this.

Thanks!

Answer 1

That's easily doable.

Find out if your video encoding device accepts DHCP, or has a predefined static address.

If it accepts DHCP, install a DHCP server package on your Ubuntu machine, configure it for eth0.

Otherwise, configure a static address for eth0 that's in the same subnet as the static IP address of the video encoding device. Make sure that subnet is distinct from the subnet you use on your router; re-configure video encoding device or router if necessary.

Configure your Ubuntu machine to otherwise leave eth0 alone, and "get the Internet" only from eth1.

Make sure forwarding is disabled on your Ubuntu machine (cat /proc/sys/net/ipv4/ip_forward should give you 0).

Details on how to do each of those steps depend on what exactly your Ubuntu machine uses (systemd? network manager?), you may have to read up documentation for those, or search the internet.