我的eth0 nmcli连接无法在 Ubuntu Bionic 18.04 LTS 上运行：
$ nmcli connection up eth0
Error: Connection activation failed: No suitable device found for this connection.
$ nmcli device status
DEVICE TYPE STATE CONNECTION
wlx0 wifi connected sebWlan
virbr0 bridge connected virbr0
eth0 ethernet unavailable --
lo loopback unmanaged --
virbr0-nic tun unmanaged --
$ nmcli device show eth0
GENERAL.DEVICE: eth0
GENERAL.TYPE: ethernet
GENERAL.HWADDR: XX:XX:XX:XX:XX:XX
GENERAL.MTU: 1500
GENERAL.STATE: 20 (unavailable)
GENERAL.CONNECTION: --
GENERAL.CON-PATH: --
WIRED-PROPERTIES.CARRIER: off
输出如下lshw：
$ sudo lshw -C network | sed -n '1,/network:/p'
*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10EC:8168]
vendor: Realtek Semiconductor Co., Ltd. [10EC]
physical id: 0
bus info: pci@0000:03:00.0
logical name: eth0
version: 06
serial: [REMOVED]
size: 10Mbit/s
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl_nic/rtl8168e-2.fw latency=0 link=no multicast=yes port=MII speed=10Mbit/s
resources: irq:17 ioport:e800(size=256) memory:f8fff000-f8ffffff memory:f8ff8000-f8ffbfff
*-network:0
有关连接的更多信息eth0 nmcli：
$ nmcli connection show eth0
connection.id: eth0
connection.uuid: 628b89fb-eafa-3afe-8179-bcaaedf9671d
connection.stable-id: --
connection.type: 802-3-ethernet
connection.interface-name: eth0
connection.autoconnect: yes
connection.autoconnect-priority: -999
connection.autoconnect-retries: -1 (default)
connection.auth-retries: -1
connection.timestamp: 1624351375
connection.read-only: no
connection.permissions: --
connection.zone: --
connection.master: --
connection.slave-type: --
connection.autoconnect-slaves: -1 (default)
connection.secondaries: --
connection.gateway-ping-timeout: 0
connection.metered: unknown
connection.lldp: default
connection.mdns: -1 (default)
802-3-ethernet.port: --
802-3-ethernet.speed: 0
802-3-ethernet.duplex: --
802-3-ethernet.auto-negotiate: yes
802-3-ethernet.mac-address: XX:XX:XX:XX:XX:XX
802-3-ethernet.cloned-mac-address: --
802-3-ethernet.generate-mac-address-mask:--
802-3-ethernet.mac-address-blacklist: --
802-3-ethernet.mtu: auto
802-3-ethernet.s390-subchannels: --
802-3-ethernet.s390-nettype: --
802-3-ethernet.s390-options: --
802-3-ethernet.wake-on-lan: default
802-3-ethernet.wake-on-lan-password: --
ipv4.method: auto
ipv4.dns: --
ipv4.dns-search: --
ipv4.dns-options: ""
ipv4.dns-priority: 0
ipv4.addresses: --
ipv4.gateway: --
ipv4.routes: --
ipv4.route-metric: -1
ipv4.route-table: 0 (unspec)
ipv4.ignore-auto-routes: no
ipv4.ignore-auto-dns: no
ipv4.dhcp-client-id: --
ipv4.dhcp-timeout: 0 (default)
ipv4.dhcp-send-hostname: yes
ipv4.dhcp-hostname: --
ipv4.dhcp-fqdn: --
ipv4.never-default: no
ipv4.may-fail: yes
ipv4.dad-timeout: -1 (default)
ipv6.method: auto
ipv6.dns: --
ipv6.dns-search: --
ipv6.dns-options: ""
ipv6.dns-priority: 0
ipv6.addresses: --
ipv6.gateway: --
ipv6.routes: --
ipv6.route-metric: -1
ipv6.route-table: 0 (unspec)
ipv6.ignore-auto-routes: no
ipv6.ignore-auto-dns: no
ipv6.never-default: no
ipv6.may-fail: yes
ipv6.ip6-privacy: 0 (disabled)
ipv6.addr-gen-mode: stable-privacy
ipv6.dhcp-send-hostname: yes
ipv6.dhcp-hostname: --
ipv6.token: --
proxy.method: none
proxy.browser-only: no
proxy.pac-url: --
proxy.pac-script: --
也许是硬件故障？
如何测试网卡是否损坏？