根据 Speedtest.net，我的速度是 100Mbps。如果我将以太网电缆插入指定的 rj45 插槽，就会出现这种情况。
如果我使用 USB LAN 适配器，速度正常 ~950Mbps
我使用Ubuntu 20.04
这是一些信息：
$ ethtool eno1
Settings for eno1:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Cannot get wake-on-lan settings: Operation not permitted
Current message level: 0x00000033 (51)
drv probe ifdown ifup
Link detected: yes
$ lshw -c network
*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:03:00.0
logical name: eno1
version: 15
serial: 38:f3:ab:a3:f9:bb
size: 1Gbit/s
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8168 driverversion=8.048.00-NAPI duplex=full ip=192.168.100.19 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
resources: irq:49 ioport:3000(size=256) memory:d1804000-d1804fff memory:d1800000-d1803fff
*-network DISABLED
description: Wireless interface
product: Realtek Semiconductor Co., Ltd.
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:04:00.0
logical name: wlan0
version: 00
serial: 74:4c:a1:be:7f:49
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
configuration: broadcast=yes driver=rtw89_pci driverversion=5.11.0-43-generic firmware=N/A latency=0 link=no multicast=yes wireless=IEEE 802.11
resources: irq:94 ioport:2000(size=256) memory:d1700000-d17fffff
*-network
description: Ethernet interface
physical id: 2
bus info: usb@2:2.3.3
logical name: eth0
serial: 00:0e:c6:82:01:1b
size: 10Mbit/s
capacity: 1Gbit/s
capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=ax88179_178a driverversion=5.11.0-43-generic duplex=half link=no multicast=yes port=MII speed=10Mbit/s