Connecting KNIME Hub to On-Premises Databases: Troubleshooting IP Whitelisting

Hi everyone,

I am currently working on connecting our KNIME Hub environment to our on-premises databases (which are naturally not exposed to the public internet).

I have been following the Hub User Guide, and so far, I have:

1.

Requested and received the dedicated IP from the KNIME team.

1.

Whitelisted this specific KNIME Hub IP on our firewall.

1.

Opened the custom database port on our public-facing IP to route traffic to the internal server.

Despite this setup, I am still unable to establish a connection. Has anyone in the community successfully implemented this direct connection approach?

Specifically, I am wondering:

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Are there any hidden requirements, additional ports, or specific protocols that need to be allowed on the firewall besides the primary DB port?

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Did any of you end up using a different architecture, such as an SSH tunnel or a reverse proxy, to solve this?

Any guidance, architecture tips, or shared experiences would be highly appreciated!

Thanks in advance!