I have just upgraded my Vigor 2860ac to 3.8.5.3_BT so I can use the 'disable EAPOL retries' work-around to protect against KRACK. However, when I upgraded my MacBook Pro to MacOS High Sierra 10.13.2 to try and mitigate against Meltdown, I found Wifi connection after waking from sleep now generally fails, unless EAPOL retries are enabled. The symptom is either getting no IP address, or only a link-local IPv4 address, or a valid-looking but non-working IPv6 address.

My iPhone 5S on iOS 11.2.1 sometimes has the same problem, but only very occasionally. My Airport Express doesn't have any issues, nor does my ancient iPad 1. So it looks like a bug in the latest MacOS. Since almost all the affected devices are patched against KRACK anyway, I'll re-enable EAPOL retries on the main SSID (I have another SSID for internet-of-dodgy-things devices, which is isolated using VLAN), and route the unpatched relics to the WEEE bin...

This may or may not be related to the iPhone 6/6S issue: I suspect not.

I get the same same thing (among other issues) with my IOS devices and anything above 3.8.5.

I tried 3.8.6 today and initially it seemed better but then got 169 addresses when returning after 15 minutes out of the house on two iPhones (temporarily fixed by toggling off/on WiFi on the iPhones). Repeated it, same result. Tried it with EAPOL disabled and enabled, same result.

Went back to 3.8.5 again. problem gone.

This may or may not be related to the iPhone 6/6S issue: I suspect not.

Whereas I suspect it is...

Question: do you have 2.4GHz & 5GHz LANs sharing the same SSID and WPA2 key? This may be linked...

maxwellhadley wrote: Question: do you have 2.4GHz & 5GHz LANs sharing the same SSID and WPA2 key? This may be linked...

Indeed I do.

I have disabled the entire 5GHz WiFi function, and re-disabled EAPOL retries on the 2.5GHz band, and now all my Apple devices seem to be working correctly. Obviously this may not be universally applicable, but at my location the neighbouring houses are widely spaced and few in number, so the 2.5GHz band is not congested (also old, slightly damp, brick internal walls restrict the usefulness of the shorter wavelengths).

I can use the 'disable EAPOL retries' work-around

If you upgrade all affected devices (phones etc.) you don't need to disable EAPOL retries (unless you have devices which can't upgrade or guests who don't).