VMG4927-B50A in bridge mode disables admin login

mss1911

I've been using the VMG42927-B50A stably in bridge mode for a year now, (It is the DSL bridge to a Mikrotik router which is the backbone of my homelab) and overall it does its job quietly and without complaint, and I have no issues. Except for one minor nagging complaint:

Once the Zyxel is put into bridge mode, GUI admin login becomes disabled! I can only re-login again by doing a factory reset. The GUI login webpage at 192.168.1.1 does, in fact, load just fine in my browser. But using "admin" and either the default password (or one that I reset it to), it fails the login with "Incorrect password" every time. It doesn't seem to be an actual incorrect password issue though. It's not a captcha issue, and it's not an issue of plugging into the correct ethernet/LAN port (I've tried them all). I understand the web interface login is disabled when a telnet session is in use, but that's not the case. In fact, telnet and ssh time out if I try to log in that way (nmap reports that ports 22 and 23 are filtered). My firewall is permissive for these scenarios, so that's not the issue either.

99.9% of the time, I have no need to log in to the device, so usually this isn't a problem. But once in a while, I need/want to log in directly to check some network diagnostics as close to the source as possible. And if I wanted to reconfigure it out of bridge mode without resetting the device, I'm out of luck. It's annoying to have to factory reset and re-configure it just to login, for multiple obvious reasons…

Is this intended behavior, that admin login is disabled when the device is in bridge mode? If not, is this a known issue? Is there a firmware update that addresses this? Am I overlooking something silly? I searched the device manual but found no clues.

Thanks!

bahecz44120

set your laptop or pc with static IP to same subnet as 192.168.1.1 and you can access to GUI under bridge mode.