I have picked up a couple of Vigor 2860 units which are both displaying exactly the same symptoms.

I am connecting an iMac directly to the Vigor using a wired ethernet cable. I have tried both setting a static IP address (192.168.1.40) on the iMac as well as letting it pick up a dynamic address (which the Vigor allocates fine). I was expecting to connect to LAN1, although I have also tried the remaining LAN2-LAN6 ports - with the same results for all 6 ports.

I can get a login screen (at 192.168.1.1) but no matter what id/pwd combination I try, the browser still shows the login screen. The combinations admin/admin, admin/<blank>, draytek/1234, and draytek/<blank> display the message "The username or password you entered is incorrect" along with the login screen. The combinations <blank>/<blank>, <blank>/admin, and <blank>/1234 display the message "User mode is off now" along with the login screen.

I have tried Safari, Firefox, and Chrome browsers on the iMac with the same results. I have also tried Edge on a PC with the same results.

I have done a factory reset.

I have also tried TFTP firmware reinstalls to versions 3.8.9.8, 3.8.4.1, and 3.8.6 from the Draytek site, and also version 3.7.1 from a mirror. In all cases I have used the .rst version to restore factory settings. In all cases the firmware install appears to complete ok - but it makes no difference to the behaviour.

I have also tried to access the CLI via a Telnet (port 23) connection without success (using netcat on the iMac). Depending on the id/password combination I may or may not get a "Bad password" message - but I never get the command line interface running.

In all cases the routers are happily ticking over with a (normal) gently flashing ACT light, but they never display any web interface other than the login page.

The fact that (a) the routers appear to be working perfectly in every other regard, and (b) are both displaying exactly the same symptoms, suggests that they are not fundamentally faulty but rather there is a configuration or connection issue.

Can anyone assist, please?

Have these come from the same source as the 2860 in this thread: https://forum.draytek.co.uk/viewtopic.php?f=14&t=23978

If so, @ admin 's response may be pertinent:-

he/she wrote:
It is 'admin/admin' but yes, some 3rd party bulk ISPs can order special OEM variants with their own settings. In those cases, they normally retain
ownership and responsibility for the product - and normally they shouldn't be resold. DrayTek support would be unable to support those products.

No idea. But it's perfectly possible given the dates.

Nevertheless I'd have expected any OEM-type issues to be resolved by blatting the firmware with a standard image.

No, quite specifically, the 3rd parties don't want people putting on "unauthorised" firmware or someone pressing the reset button and then complaining to the service provider that their service doesn't work. If the SP needs the user do do a factory reset, they want it back to THEIR defaults, not the default public ones.