Slow speed on Linux laptop

My laptop unfortunately doesn't have an ethernet port, or I'd plug in right away. I replaced the wifi chip after problems began and I couldn't find a software or configuration issue.

I appreciate those details @phiboy! It also really helps to know this only happens when connected to the home network. Is this the only device having issues?

Yes, my other devices are fine on my home network.

Do you know if Linux had an update around the time this issue started @phiboy?

I didn't have a major update. I did have the same issue across multiple distros, though, so this doesn't seem to be limited to a particular distro or kernel. It looks like the other users in this topic are doing similar troubleshooting steps, maybe we can find something causing an issue that's across all of us.

• My gateway is model CGM4331COM, have there been any updates or changes to its firmware recently?
• Has Xfinity done any upgrades to its infrastructure that could impact some users?
• I've had this issue in Fedora and Mint, both only on my home network (as reported by the other users, other networks are fine). Is there some kind of trigger in my gateway or network that could have issues with a particular OS?
• Another user believes that the router sets the width to 20. Is that something that can be adjusted to test?

Where can you see the width?

And which distro are you on? Just trying to find if there's some commonality between those of us having this issue.

@Parad0x763 Thanks for reaching out to us regarding your internet speed. I do apologize for any inconvenience this may have caused you, and I would be more than happy to assist you today.  Please send us a direct chat message with your full name and complete service address to “Xfinity Support”. To do so, click on the chat icon located at the top right of this forum's page.
 
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@XfinityCarolyn​ 

Please circle back here and post any possible solutions for the issue here in these open public forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

What distro are you using?

Thank you for sharing such detailed troubleshooting steps @user_wg2q89! Are you using a Xfinity gateway or your own personal modem/router? 

Have you tried splitting your bands into separate names? I've seen this solve the issue for a few customers, as it forces your laptop to connect directly to a clean, high-speed band.

Yes, I am using an Xfinity gateway (model XB7). I have not tried split bands - but I did try connecting to both 5g and 2.4g. I am hesitant to split bands as i have many devices auto connecting to the network and don't want to have to change the network name. What I wish I could try is connecting to a different 5g channel, but the gateway is managed and I don't have any control over that.  

@phiboy​ I am using Fedora 44. The problem also was present on Fedora 43.

Thank you for sharing and being our eyes and ears on the other end, user_wg2q89. Are you using any additional equipment alongside your Xfinity Gateway? Is this issue isolated to your Linux device?

Hi there, @user_p1baho. We are glad to further help. Are you seeing the full speed when connected with an ethernet cable, just not on WiFi? Our modems have advanced intelligence so you may not be able to update some settings. They are automatically managed. Are you using a separate router along with the gateway modem? 

This isn't a linux issue. The issue is Xfinity not managing their equipment properly. There is now a patch that provides a workaround since Xfinity is unwilling to review this issue that they have created - https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless.git/commit/?id=711a9c018ad252b2807f85d44e1267b595644f9b

More details here:

https://lore.kernel.org/linux-wireless/CACM6vn5hAWv1rRNNByS=5RzAcxhC5R8BpvjdaDVb7iG+o6W5+A@mail.gmail.com/T/#m1717afcb67213d14956899c6ba7eaad514a94f6c - Discussion among kernel devs

https://github.com/ublue-os/bazzite/issues/4676

https://github.com/WoodyWoodster/mac80211-mcs-patch/issues/1

I wonder when we can expect to see this patch show up in the kernel. Fedora 44 is currently on 7.0.10 and nothing yet. Or hopfully xfinity can take a serious look at this. I would imaging there's a lot of linux users that are Xfinity customers