我在ThinkPad P72。更新到 20.04 后，WiFi 每天掉线几次，每小时掉线十几次，并且很难重新连接（如果我关闭 WiFi 然后再打开，它有时会重新连接），除非我重新启动。我的 WiFi 点不会对其他操作系统造成连接问题。
我听一位最近升级到 20.04 的朋友说，他们也遇到了 WiFi 随机连接中断的情况。
笔记：我不知道什么样的调试或日志文件或诊断在这里有用，但如果您在评论中要求具体信息，我会尽力提供。
编辑：这些断开连接事件根本不会显示出来/var/log/syslog。
$ lspci -knn | grep Net -A3; rfkill list
00:14.3 Network controller [0280]: Intel Corporation Wireless-AC 9560 [Jefferson Peak] [8086:a370] (rev 10)
Subsystem: Intel Corporation Wireless-AC 9560 [Jefferson Peak] [8086:0030]
Kernel driver in use: iwlwifi
Kernel modules: iwlwifi
0: tpacpi_bluetooth_sw: Bluetooth
Soft blocked: no
Hard blocked: no
1: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
2: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
将 2.4Ghz 设置为“自动”频道
% iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:2.417 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=48 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=57/70 Signal level=-53 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:382 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
切换到 5GHz 频段的第 36 频道后：
$ iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:5.2 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=48 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=47/70 Signal level=-63 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:6 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
切换到 5GHz 频段的第 48 频道后：
$ iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:5.24 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=54 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=51/70 Signal level=-59 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:13 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
切换到 5 GHz 频段的 149 频道后：
$ iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:5.745 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=54 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=51/70 Signal level=-59 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:10 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
切换到5GHz频段的161频道后：
$ iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:5.805 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=54 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=54/70 Signal level=-56 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:1 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
切换到 2.4 GHz 频段的频道 1 后：
$ iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:2.412 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=54 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=56/70 Signal level=-54 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:6 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
切换到 2.4 GHz 频段的第 6 频道后：
$ iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:2.437 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=48 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=60/70 Signal level=-50 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:8 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
切换到 2.4 GHz 频段的第 11 频道后：
$ iwconfig
wlp0s20f3 IEEE 802.11 ESSID:"R910a-2DB972"
Mode:Managed Frequency:2.462 GHz Access Point: F4:63:49:2D:B9:72
Bit Rate=54 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr:off Fragment thr:off
Power Management:off
Link Quality=60/70 Signal level=-50 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:1 Missed beacon:0
lo no wireless extensions.
enx5282d5c87b2f no wireless extensions.
enp0s31f6 no wireless extensions.
$ iwlist wlp0s20f3 freq
wlp0s20f3 32 channels in total; available frequencies :
Channel 01 : 2.412 GHz
Channel 02 : 2.417 GHz
Channel 03 : 2.422 GHz
Channel 04 : 2.427 GHz
Channel 05 : 2.432 GHz
Channel 06 : 2.437 GHz
Channel 07 : 2.442 GHz
Channel 08 : 2.447 GHz
Channel 09 : 2.452 GHz
Channel 10 : 2.457 GHz
Channel 11 : 2.462 GHz
Channel 12 : 2.467 GHz
Channel 13 : 2.472 GHz
Channel 36 : 5.18 GHz
Channel 40 : 5.2 GHz
Channel 44 : 5.22 GHz
Channel 48 : 5.24 GHz
Channel 52 : 5.26 GHz
Channel 56 : 5.28 GHz
Channel 60 : 5.3 GHz
Channel 64 : 5.32 GHz
Channel 100 : 5.5 GHz
Channel 104 : 5.52 GHz
Channel 108 : 5.54 GHz
Channel 112 : 5.56 GHz
Channel 116 : 5.58 GHz
Channel 120 : 5.6 GHz
Channel 124 : 5.62 GHz
Channel 128 : 5.64 GHz
Channel 132 : 5.66 GHz
Channel 136 : 5.68 GHz
Channel 140 : 5.7 GHz
Current Frequency:2.417 GHz (Channel 2)
答案1
我的笔记本电脑经常出现这个问题，大约半年后，我意识到 ubuntu 不能很好地处理某些 wifi 路由器信号。为我解决这个问题的方法是禁用 IPv6，并在路由器上只选择一个频道。（之前是动态的）。我在家里不再遇到问题。不幸的是，如果我在学校或咖啡馆，问题就会再次出现。