I have a 2860n+ in which the DHCP server is disabled, as I have a separate DHCP server running on a Linux box on my LAN. This has been working fine for years.

Following the email from Draytek, I updated my 2860n+ from 3.8.5_BT to 3.8.8_BT a week ago. I then found over the next couple of days that my iPad (iOS 11.3) would keep losing its DHCP lease and reverting to a 169.254.x.x address which of course had no connectivity. Briefly turning Airplane Mode on and off again would make it renew its lease, and it was then fine for a few minutes or tens of minutes, before losing its address again.

After a couple of days of being frustrated by that behaviour, I reverted the router to 3.8.5, and the problem stopped happening. So it was definitely something to do with the router firmware.

Of course, I don't know whether that problem may have been introduced in 3.8.6 or 3.8.7 as I skipped those versions. I may have to try them to find out. But since the 3.8.8 update was related to the behaviour of DHCP traffic, it seems likely to be related.

Has anyone else observed anything similar? Any word from Draytek?

Thanks
Tony

Yes, exactly this: see https://forum.draytek.co.uk/viewtopic.php?f=19&t=22011 . The summary is the 5GHz WiFi is broken for Apple device on current software 2860 & 2862. If you turn off 5GHz networking, it works (at least it does for me). Hopefully this will get fixed one day soon!

Interesting thread, thank you. Would be interesting to know if Draytek have acknowledged there is a problem with Apple devices on 5GHz and intend to fix it!

For now, I'll stay back on 3.8.5. I think the CSRF risk for my usage pattern is pretty low anyway, and all my devices get their DHCP and DNS from a Linux box, not the router.

Try 3.8.9 which has just been released.

This looks to have resolved the issue, certainly on the 2862 anyway.

The firmware is only on the main site not on the UK support site yet.

Thank you! I'll go and look for it...

Interestingly, the Release Notes don't make any mention of fixing an issue with Apple devices on 5GHz...

A couple of comments:

I'm engaging with Draytek support about a few issues, one of them being 5GHz wifi against my 2862. We also touched on 3.8.9 release.

Draytek support's assertion is that Apple devices may be more stable with EAPOL disabled (personally I find it the other way around - My late 2016 MBP will not get an IP with EAPOL off).

Re 3.8.9 UK release (again information is for 2862). It *is* due for UK release within the next few days (it was implied that it was being tested at the moment, and I guess release would be subject to that testing not unearthing significant issues), so if you want to stay on the localised code, you should not need to wait long.