Re: Wi-Fi speeds degrade from 600Mps to 30Mps while using WPA2 security, but not on open network, shortly after ISP firmware upgrade.

[Pablo MARTIN-GOMEZ <pablomg@eskapa.be>]

Hello,
On 16/04/2026 10:47, Benson Bear wrote:
> Hi folks, I've never posted here before, don't know much about wireless, but
> am having a big problem I have been trying to solve for a week. I've been
> googling and ai chatting non-stop but finally after reading the info
> page about the
> list figured it would probably be acceptable to send this message.
> 
> BRIEFEST SUMMARY: There was a firmware update in Rogers's (Canada) XB7 Gateway,
> and subsequently my Wi-Fi transfer speeds degraded badly on all three
> Linux notebooks I have. Fully up to date notebooks, running Fedora 43 and
> 42 with most recent kernel 6.19.11. Two different NICs: RTL8852BE and Intel
> 7265 (rev 59). Wired machines and phones are unaffected.
> 
> The machines all connect with high transfer rates of around
> 800-1000Mbs on the 5G band,
> with an 80Mhz wide channnel, and MCS level ranging from 7 to 11 (HE and VHT).
> 
> Transfer speeds using WPA2 security have dropped in the one case (RTL)
> from 600Mbps to
> about 30Mbps. (Using internet speed test but iperf3 gives similar). The other
> cases are similar.
When traffic is capped around 30-50Mbps, the usual suspect is
aggregation not being setup.
> 
> BUT the transfer using no network security is still what it used to
> be! It is simply
> the enabling of WPA2 that brings them to their knees.
If I had to guess, this is an issue with PMF. Either the STA or the AP
considers PMF is activated and the other one not; so the action frames
that set up a BA session are dropped.

Check
`/sys/kernel/debug/ieee80211/phy<n>/netdev\:<devname>/stations/<bssid>/flags`
on your notebooks if there is `MFP` in the flags
> 
> So it seems to be a problem related to WPA2, and at a lower level in the
> stack of modules, since it happens on two different NICs?
You can try a few things:
- build a master wpa_supplicant from source and replace the Fedora's
binaries
- use a raw wpa_supplicant connection and set ieee80211w=0 in the config
file
- switch the backend of NetworkManager to iwd
- update the security to WPA3
> 
> I suspected for a long time that it was a firmware bug in the gateway, but
> now I am starting to wonder. I have no solid evidence of that except that
> Windows works fine on the same gateway and the same machine.
> 
> All three machines work well on another network I have occasional access
> to, and have worked fine on this network until about a week ago.
> 
> I have ordered another router that I hope I can use to solve the
> immediate practical problem, but I would really like to figure out
> what is going on and contribute what I can to fixing it, even if only
> by being sent out to gather potentially useful data.
> 
> Thank you.
> 

Pablo MG