Question about Docker IPs

[Korval]

I'm a novice at networking, so apologies if this should be obvious. I'm just learning as I go. I've recently set up my first Terramaster NAS and have finished getting the most important file-access stuff going. Then I decided to try my hand at learning basic Docker stuff.

I have one simple container working (for my e-reader) and had just started looking at the post-installation steps for an immich server. I'm following the guide at https://docs.immich.app/install/synology (the Synology guide seemed to match Terramaster pretty well). It suggested noting the container's IP and using it accessing the web app. As far as I can tell, the IP addresses shown in the container manager are bogus. For both of the containers that I tried, web access works with either my internal IP (i.e., 192.168.0.x) or my current external IP--after forwarding the appropriate port, of course. Am I missing something? Are the containers' IP addresses "virtual" like the IP address shown in the TNAS's Control Panel under "Remote Access" (and therefore seemingly useless)?

[CursaYang]

A Docker container IP is usually an internal address within the container's virtual network, mainly used for communication between containers or for direct access under specific network configurations. You can access the application through the NAS's LAN IP and port mapping. The container IP is not fake — it's just that it typically cannot be accessed directly from the LAN.

[Korval]

Got it. Thank you. Rereading the help page, I see now that it said to note the IP for firewall exceptions "to allow communication between the Immich containers." And when in the following step to access the web app via the IP address, it doesn't specifically say which IP address. It was my own assumption that they meant the one previously discussed rather than one they hadn't mentioned.

[outkastm]

You can find a step by step installation guide for TM NAS.
https://tmnascommunity.eu/download/immich/