Unable to connect to Core20 server from outside my VLAN

[Jeff Lane ]

We are installing Core20 onto a Dell R340 Server. The server has two network devices.

Each network device has an IP on different address blocks, both part of the same VLAN.

When Core20 is installed on the machine, I am unable to connect to that machine from outside my VLAN (even when I have access to the VLAN from outside the physical network via a VPN). In order to SSH to the server, I have to first SSH to someting physically close to this one. Only then can I connect to the machine via SSH.

If I redeploy this machine with the latest 20.04 Server image, networking works exactly as expected and I can connect to it remotely without the use of a local jump box.

So there is something weird/hinky going on with Core20 networking, etiher internal routing or who knows what. But, this is a big issue, I should be able to connect to it via SSH regardless of where I'm connecting from, as long as the network allows such remote connections.

So:

Expected Results:
I can SSH to my R340 server remotely when Core20 is deployed on it.

Observed Results:
I must use a local jump host to connect to my R340 when Core20 is deployed on it.
This DOES NOT happen when Classic is deployed to this machine.

[Maciej Borzecki (maciek-borzecki)]

Might be something with netplan or otherwise the network configuration. Anything suspicious in the journal about VLANs?

[Launchpad Janitor (janitor)]

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