Anyone know what this means in the interface log? private-5g is the name of the 5GHz master interface.
private-5g detect LAN
Also, does this page need some work although I guess it’s about the wireless topic, not interface?
Detect LAN, is from Detect Internet feature https://help.mikrotik.com/docs/display/ROS/Detect+Internet
Thanks for that. Another bit of idle curiosity opens up more questions! I’ve read the page you’ve referenced and I’m intrigued why ether2 is showing as WAN. I assume this means “wide area network”. ether2 is connected to a unmanaged switch on the LAN into which my PC, server etc are connected. ether3 and ether4 are connected directly to devices. I would expected ether2 to say LAN? Unless my understanding of wide area network is wrong.
Columns: NAME, STATE, STATE-CHANGE-TIME, CLOUD-RTT
# NAME STATE STATE-CHANGE-TIME CLOUD-RTT
0 ether1 internet 2024-01-29 10:46:31 65ms
1 ether2 wan 2024-01-31 12:56:16
2 ether3 lan 2024-01-31 13:04:23
3 ether4 lan 2024-01-31 13:02:36
4 ether5 no-link 2024-01-29 10:46:22
5 private-5g lan 2024-01-31 11:15:19
6 private-2g lan 2024-01-31 13:02:52
7 bridge wan 2024-01-29 10:46:34
8 guest-2g lan 2024-01-29 10:46:32
9 guest-5g lan 2024-01-31 11:18:29
10 guest-vlan wan 2024-01-29 10:46:22
Also, should I be worried about this? I’m not aware that I enabled this service and can’t see where it is enabled.
Note that Detect Internet can install DHCP clients, default routes, DNS servers and affect other facilities.
Use with precaution, and after enabling the service, check how it interferes with your other configuration.
Answering my own question here, it’s configured via “Detect Internet” on the Interface List:
My new ax2 (ROS 7) had “Detect Interface” set to all and none in the rest. A client’s RB4011iGS had it turned off (ROS 6). Just to confuse me even more, I’ve enabled it at the client site and ether2 and ether3 are showing LAN as I expected. These two ports are, like my home set-up, connected to (many) more switches.
Most people simply disable that function.
Reading the help page here:
https://help.mikrotik.com/docs/display/ROS/Detect+Internet
Note that Detect Internet can install DHCP clients, default routes, DNS servers and affect other facilities.
Use with precaution, and after enabling the service, check how it interferes with your other configuration.
it seems like a sort of auto-magical, non-deterministic gizmo without a declared real-world utility/usage, not surprised that is mostly disabled by the users.
I cannot seem to find a possible use case for it, except maybe some scripts, but there must be more (untold on the help page) to it, to only categorize (rightly or wrongly) the interfaces by type of connection there is no need to change DHCP, routes or DNS settings. 
It was off on that older client router and when I reset on my hAP ax2 to default, it was also off. I’m very anal about recording individual changes to main router configurations and considering I had no idea where the configuration was, I doubt I’d turned it on. Therefore I assume that Mikrotik have changed the default configuration from on (circa November 2023) from on and the current version (default off).
Not surprised as it’s clearly confusing me at home 
I’m guessing that it’s been off in default configuration like forever but somehow got enabled recently. As this ax2 is my experimentation device, I’m regularly backing up the configuration. The following line appeared in January:
/interface detect-internet
set detect-interface-list=all
The only real-world use case is the smartphone apps. With it enabled, you can get a nice graph of internet usage in the app. That’s about it.
Worse, in the iOS app, the Home Screen has a yellow warning “Internet Detect Not Active” – so seems like something you’d want to enable, right? And in the app, you just tap it & say “Yes” to enable Detect Internet…
But since it works on all interfaces by default, not just the WAN interface-list… wacky things can happen if you have a non-default configuration. The main offender is one of it’s actions (in something that purports to “just” detect internet), is adding a DHCP client on an interface (if it doesn’t have internet and no dhcp-client configured).
Basically I think someone at Mikrotik thought it was a good idea for the apps, but then no every come back to clean it up to make it more useful. e.g. it could be useful in script/firewall, but there are no events for on-change & you can’t customize it’s detection methods (e.g. disable the nasty dhcp-client test).