我将电缆插入 USB 3.0 插槽，然后启用网络共享，并且列出了接口，但没有实际连接——当我尝试 ping 任何内容时，出现名称解析暂时失败错误：
$ ip link show
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: enp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN mode DEFAULT group default qlen 1000
link/ether 90:2b:34:96:0c:2e brd ff:ff:ff:ff:ff:ff
4: enp2s0u2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 1000
link/ether 2e:6a:a2:21:34:32 brd ff:ff:ff:ff:ff:ff
$ ping google.com
ping: google.com: Temporary failure in name resolution
以下是我的手机通过 USB 2.0 端口连接时出现的情况（仅接口名称不同）：
$ ip link show
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: enp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN mode DEFAULT group default qlen 1000
link/ether 90:2b:34:96:0c:2e brd ff:ff:ff:ff:ff:ff
3: enp0s18f2u2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN mode DEFAULT group default qlen 1000
link/ether 8e:fd:99:2b:1d:bf brd ff:ff:ff:ff:ff:ff
以下是消息在我将电缆从 USB 2.0 插槽拔下并将其插入 3.0 插槽后显示：
[ 1024.836805] usb 1-2: USB disconnect, device number 3
[ 1024.839044] rndis_host 1-2:1.0 enp0s18f2u2: unregister 'rndis_host' usb-0000:00:12.2-2, RNDIS device
[ 1024.894912] audit: type=1130 audit(1658489981.539:58): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=NetworkManager-dispatcher comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
[ 1027.140095] usb 8-2: new high-speed USB device number 2 using xhci_hcd
[ 1027.263472] usb 8-2: device descriptor read/64, error -32
[ 1027.370108] xhci_hcd 0000:02:00.0: WARN urb submitted to disabled ep
[ 1027.370119] xhci_hcd 0000:02:00.0: WARN urb submitted to disabled ep
[ 1027.370124] xhci_hcd 0000:02:00.0: WARN urb submitted to disabled ep
[ 1027.493475] usb 8-2: device descriptor read/64, error -2
[ 1027.723432] usb 8-2: new high-speed USB device number 3 using xhci_hcd
[ 1027.869225] usb 8-2: New USB device found, idVendor=0e8d, idProduct=2008, bcdDevice= 2.23
[ 1027.869237] usb 8-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1027.869242] usb 8-2: Product: Nokia 2.2
[ 1027.869246] usb 8-2: Manufacturer: HMD Global
[ 1027.869250] usb 8-2: SerialNumber: HZAL1670CAJ61222625
[ 1034.236902] usb 8-2: USB disconnect, device number 3
[ 1034.653424] usb 8-2: new high-speed USB device number 4 using xhci_hcd
[ 1034.796137] usb 8-2: New USB device found, idVendor=0e8d, idProduct=2004, bcdDevice= 2.23
[ 1034.796148] usb 8-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1034.796153] usb 8-2: Product: Nokia 2.2
[ 1034.796157] usb 8-2: Manufacturer: HMD Global
[ 1034.796161] usb 8-2: SerialNumber: HZAL1670CAJ61222625
[ 1034.801868] rndis_host 8-2:1.0 usb0: register 'rndis_host' at usb-0000:02:00.0-2, RNDIS device, a2:52:0d:24:48:2c
[ 1034.841206] rndis_host 8-2:1.0 enp2s0u2: renamed from usb0
然后回到2.0版本：
[ 1368.903916] usb 8-2: USB disconnect, device number 4
[ 1368.904118] rndis_host 8-2:1.0 enp2s0u2: unregister 'rndis_host' usb-0000:02:00.0-2, RNDIS device
[ 1372.179998] usb 1-2: new high-speed USB device number 4 using ehci-pci
[ 1372.303316] usb 1-2: device descriptor read/64, error -32
[ 1372.557558] usb 1-2: New USB device found, idVendor=0e8d, idProduct=2008, bcdDevice= 2.23
[ 1372.557570] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1372.557576] usb 1-2: Product: Nokia 2.2
[ 1372.557580] usb 1-2: Manufacturer: HMD Global
[ 1372.557583] usb 1-2: SerialNumber: HZAL1670CAJ61222625
[ 1377.290696] usb 1-2: USB disconnect, device number 4
[ 1377.689998] usb 1-2: new high-speed USB device number 5 using ehci-pci
[ 1377.837516] usb 1-2: New USB device found, idVendor=0e8d, idProduct=2004, bcdDevice= 2.23
[ 1377.837527] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1377.837532] usb 1-2: Product: Nokia 2.2
[ 1377.837536] usb 1-2: Manufacturer: HMD Global
[ 1377.837539] usb 1-2: SerialNumber: HZAL1670CAJ61222625
[ 1377.840158] rndis_host 1-2:1.0 usb0: register 'rndis_host' at usb-0000:00:12.2-2, RNDIS device, 46:37:c6:dd:89:18
[ 1377.878982] rndis_host 1-2:1.0 enp0s18f2u2: renamed from usb0
事实上，还有一个问题：将电缆重新插入任何插槽后，无论 USB 是什么版本，我的连接速度都会急剧下降：1 兆少量每秒左右。它持续到我重新启动系统。
以下是消息系统启动时显示有关 USB 端口的信息：
[ 1.005525] usb 1-2: new high-speed USB device number 2 using ehci-pci
[ 1.153435] usb 1-2: New USB device found, idVendor=0e8d, idProduct=2008, bcdDevice= 2.23
[ 1.153440] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 1.153443] usb 1-2: Product: Nokia 2.2
[ 1.153444] usb 1-2: Manufacturer: HMD Global
[ 1.153445] usb 1-2: SerialNumber: HZAL1670CAJ61222625
这里我第一次启用网络共享：
[ 36.579734] usb 1-2: USB disconnect, device number 2
[ 36.996821] usb 1-2: new high-speed USB device number 3 using ehci-pci
[ 37.144352] usb 1-2: New USB device found, idVendor=0e8d, idProduct=2004, bcdDevice= 2.23
[ 37.144356] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 37.144358] usb 1-2: Product: Nokia 2.2
[ 37.144359] usb 1-2: Manufacturer: HMD Global
[ 37.144360] usb 1-2: SerialNumber: HZAL1670CAJ61222625
[ 37.419554] usbcore: registered new interface driver cdc_ether
[ 37.483531] rndis_host 1-2:1.0 usb0: register 'rndis_host' at usb-0000:00:12.2-2, RNDIS device, 9e:fd:13:0f:49:54
[ 37.483618] usbcore: registered new interface driver rndis_host
[ 37.496873] rndis_host 1-2:1.0 enp0s18f2u2: renamed from usb0
另外，检查这个相关问题。