Join Log in
Score:0
Trippingbillies41 avatar Ubuntu

Ubuntu 20.04 Wifi Keeps Dropping

in flag
Trippingbillies41

I recently moved and set up my system with a new wifi router. Since then, my Ubuntu randomly loses wifi every 5-10 minutes. I have to turn off the wifi setting on my computer and turn it back on to regain internet. Sometimes the wifi will stop and the network history will show full usage and my computer will freeze, requiring a restart. I upgraded to a comcast wifi 6 router. My wifi card is a Intel Corporation Wi-Fi 6 AX200 (rev 1a). Does anyone know how to fix this?

1646
2 + 3
waltinator avatar
it flag
waltinator
Look at the logs! `sudo journalctl -b 0 -u NetworkManager`. Read `man journalctl`.
1
Reply
Trippingbillies41 avatar
in flag
Trippingbillies41
I've tried this, but I do not know what I am looking for.
0
Reply
waltinator avatar
it flag
waltinator
Follow the progress of Network Manager, step by step, and observe what it says it is doing. Carefully read each line. Understand the message - Is informative, does it describe unusual behavior, does the date/time correspond to an "event"?
0
Reply
Score:2
chili555 avatar Ubuntu
cn flag
chili555

Your wireless may be dropping because of power management; that is, the feature where the card partially powers down to save battery power during periods of inactivity and then, ideally, powers back up seamlessly when activity resumes. Let's disable power saving to see if it helps. From the terminal:

sudo sed -i 's/3/2/' /etc/NetworkManager/conf.d/*

Your wireless may be dropping because the channel to which it was connected has suddenly changed.

Please check the settings in the router. WPA2-AES is preferred; not any WPA and WPA2 mixed mode and certainly not TKIP. Second, if your router is capable of N speeds, you may have better connectivity with a channel width of 20 MHz in the 2.4 GHz band instead of automatic 20/40 MHz, although it is likely to affect N speeds. I recommend a fixed channel, either 1, 6 or 11, rather than automatic channel selection. Also, be certain the router is not set to use N speeds only; auto B, G and N is preferred.

Your wireless may be dropping because there are two wireless access points with the same name and password. This is typical when you have a 2.4 gHz segment and a 5 gHz segment of the same router. Your wireless may be roaming, looking for a better connection. If this is the case, I suggest that you rename the access points; something like myrouter2.4 and myrouter5.

After making these changes, reboot the router.

Next, I recommend that your regulatory domain be set explicitly. Check yours:

sudo iw reg get

If you get 00, that is a one-size-maybe-fits-all setting. Find yours here: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2 Then set it temporarily:

sudo iw reg set IS

Of course, substitute your country code if not Iceland. Set it permanently:

sudo nano /etc/default/crda

Change the last line to read:

REGDOMAIN=IS

Proofread carefully, save and close the text editor.

Is there any improvement?

0 + 1
Trippingbillies41 avatar
in flag
Trippingbillies41
I've tried that, my REGDOMAIN has been equal to =US for two days. Still sporadic disconnections.
0
Reply
it flag
Diogo Gomes
My internet was constantly dropping. I had the same internet connection name for both frequencies. I've fixed the issue by giving a different name for each 2.4 and 5 gHz connections.
0
Reply
Score:0
waltinator avatar Ubuntu
it flag
waltinator

Check your WiFi MTU, using

ip link

also notice your WiFi interface's name.

The MTU (Maximum Transmission Unit) is the size of the largest packet that can be sent in a single network transmission. If a packet exceeds the MTU of a link, the data must be split into multiple packets (fragmented). These multiple packets must be sent over the link, received, acknowledged, and reassembled at the far end. If your link is misconfigured, and you have to fragment every packet you send, your actual data transfer rate drops.

Ethernet (wired) networks use an MTU of 1500 bytes.

Due to additional per packet overhead for WiFi (8 bytes PPPoE header), WiFi uses an MTU of 1492.

Your MTU should be set by your DHCP server, check your router's config.

You can set your own MTU (setting does not persist over restarts) with

sudo ip link set dev name mtu 1492

where "name" is the interface name from above.

Here's an example:

walt@squid:~(0)$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp63s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:24:21:7f:e5:1c brd ff:ff:ff:ff:ff:ff
3: wlxf46d04b1790f: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DORMANT group default qlen 1000
    link/ether f4:6d:04:b1:79:0f brd ff:ff:ff:ff:ff:ff
walt@squid:~(0)$   sudo ip link set dev wlxf46d04b1790f mtu 1492
[sudo] password for walt: 
walt@squid:~(0)$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp63s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:24:21:7f:e5:1c brd ff:ff:ff:ff:ff:ff
3: wlxf46d04b1790f: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 qdisc mq state UP mode DORMANT group default qlen 1000
    link/ether f4:6d:04:b1:79:0f brd ff:ff:ff:ff:ff:ff

My WiFi "interface name" is "wlxf46d04b1790f".

NOTE: packet fragmentation is not logged, as it's a "feature" of the Data Link layer (layer 2 in the OSI model).

0 + 1
Trippingbillies41 avatar
in flag
Trippingbillies41
Ok, I set my WiFi interface to 1492 MTU. It was at 1500. Do I have to do this everytime I turn my computer on?
0
Reply
ธงชาติไทย
Elon Musk
I sit in a Tesla and translated this thread with Ai:

mangohost

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.