Ubuntu18.04网络管理器不为USB以太网设备创建新连接

Question

问题是，当我添加usb以太网设备时，网络管理器不会为添加的设备创建新的连接。它正确地管理它，但它被困在断开状态，直到您手动添加与网络管理器的连接。这不是常规安装的行为方式，它让网络管理器在内存中创建连接并将其附加到您刚刚插入的设备上。

我使用替代安装程序安装ubuntu，并使用一个预置文件来设置机器。在预置文件中，我们为ubuntu桌面和其他几个桌面安装了所有软件包。这可能与这些问题有关。可能是预置文件的相关部分，其他所有内容都与分区和加密有关。

d-i netcfg/choose_interface select auto
tasksel tasksel/first multiselect ubuntu-desktop
d-i pkgsel/include string ssh build-essential python-minimal ubuntu-desktop vim

以这种方式安装的原因超出了这个问题。它可以被改变，但是这个已经用这种方式设置并修复它们的错误效果设备不能被“重新安装”。

当主板上有以太网连接和两个usb以太网连接时nmcli输出的示例。

eno1: connected to netplan-eno1

enx8cae4cfea138: connected to Wired connection 1

enx00e08f005933: disconnected
        "Realtek USB 10/100/1000 LAN"
        1 connection available
        ethernet (r8152), 00:E0:8F:00:59:33, hw, mtu 1500

在安装过程中，网络管理器似乎在/etc/NetworkManager/system-connections/中创建了“有线连接1”，然后将其应用于任何连接的usb设备。eno1似乎在使用netplan生成的东西。我不知道我应该在哪里寻找所有这些，这台Frankenstein机器产生的netplan、networkmanager和systemd的组合有点让人困惑，但这里有一些相关的配置文件。这些都是未触及的新安装。

/etc/NetworkManager/NetworkManager.conf

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false

[device]
wifi.scan-rand-mac-address=no

/etc/NetworkManager/system-connections/有线连接1

[connection]
id=Wired connection 1
uuid=5da83520-ee6d-4e0a-a21d-27d0c9eb5b77
type=802-3-ethernet

[802-3-ethernet]

[ipv4]
method=auto

[ipv6]
method=auto
ip6-privacy=2

/etc/netplan/01-netcfg.yml

# This file describes the network interfaces available on your system
# For more information, see netplan(5)
network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      dhcp4: yes

/etc/netplan/01-网络经理-all.yaml

# Let NetworkManager manage all devices on this system
network:
  version: 2
  renderer: NetworkManager

/var/run/NetworkManager/system-connections/netplan-eno1

[connection]
id=netplan-eno1
type=ethernet
interface-name=eno1

[ethernet]
wake-on-lan=0

[ipv4]
method=auto

[ipv6]
method=ignore

/etc/网络/接口

source-directory /etc/network/interfaces.d

interfaced.d是一个空目录。

NetworkManager是一个启用的服务，而systemd不启用。

当我将usb以太网插入设备时，网络管理器中的日志，当usb以太网无法为设备分配连接时。

Aug 09 15:06:25 <computer> NetworkManager[1011]: <info>  [1565388385.0741] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/8)
Aug 09 15:06:25 <computer> NetworkManager[1011]: <info>  [1565388385.1246] devices added (path: /sys/devices/pci0000:00/0000:00:14.0/usb2/2-8/2-8.1/2-8.1:1.0/net/enx8cae4ce9dc04, iface: enx8cae4ce9dc04)
Aug 09 15:06:25 <computer> NetworkManager[1011]: <info>  [1565388385.1246] device added (path: /sys/devices/pci0000:00/0000:00:14.0/usb2/2-8/2-8.1/2-8.1:1.0/net/enx8cae4ce9dc04, iface: enx8cae4ce9dc04): no ifupdown configuration found.
Aug 09 15:06:25 <computer> NetworkManager[1011]: <info>  [1565388385.1247] device (enx8cae4ce9dc04): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'external')
Aug 09 15:06:28 <computer> NetworkManager[1011]: <info>  [1565388388.4869] device (enx8cae4ce9dc04): carrier: link connected
Aug 09 15:06:28 <computer> NetworkManager[1011]: <info>  [1565388388.4897] device (enx8cae4ce9dc04): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')

当我将usb设备插入我自己的命运时，来自网络管理器的日志。

Aug 09 15:04:25 <computer> NetworkManager[2382]: <info>  [1565388265.0379] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/11)
Aug 09 15:04:25 <computer> NetworkManager[2382]: <info>  [1565388265.0961] devices added (path: /sys/devices/pci0000:00/0000:00:14.0/usb2/2-4/2-4:1.0/net/enx8cae4ce9dc04, iface: enx8cae4ce9dc04)
Aug 09 15:04:25 <computer> NetworkManager[2382]: <info>  [1565388265.0961] device added (path: /sys/devices/pci0000:00/0000:00:14.0/usb2/2-4/2-4:1.0/net/enx8cae4ce9dc04, iface: enx8cae4ce9dc04): no ifupdown configuration found.
Aug 09 15:04:25 <computer> NetworkManager[2382]: <info>  [1565388265.0964] device (enx8cae4ce9dc04): state change: unmanaged -> unavailable (reason 'managed', sys-iface-state: 'external')
Aug 09 15:04:25 <computer> NetworkManager[2382]: <info>  [1565388265.4268] keyfile: add connection in-memory (15600b6f-63ad-37ae-9f6c-2f2e28f05489,"Wired connection 4")
Aug 09 15:04:25 <computer> NetworkManager[2382]: <info>  [1565388265.4272] settings: (enx8cae4ce9dc04): created default wired connection 'Wired connection 4'
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5839] device (enx8cae4ce9dc04): carrier: link connected
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5877] device (enx8cae4ce9dc04): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5899] policy: auto-activating connection 'Wired connection 4'
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5926] device (enx8cae4ce9dc04): Activation: starting connection 'Wired connection 4' (15600b6f-63ad-37ae-9f6c-2f2e28f05489)
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5935] device (enx8cae4ce9dc04): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5949] device (enx8cae4ce9dc04): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5961] device (enx8cae4ce9dc04): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.5972] dhcp4 (enx8cae4ce9dc04): activation: beginning transaction (timeout in 45 seconds)
Aug 09 15:04:28 <computer> NetworkManager[2382]: <info>  [1565388268.6012] dhcp4 (enx8cae4ce9dc04): dhclient started with pid 25848
Aug 09 15:04:28 <computer> dhclient[25848]: DHCPREQUEST of 10.15.1.104 on enx8cae4ce9dc04 to 255.255.255.255 port 67 (xid=0x46cb0eef)

设备日志中缺少的是“在内存中创建连接”行。是否有什么设置是我遗漏的网络管理器，使它能够这样做？

Answer 1

我还得到了“载波改变”错误，导致频繁断开与我的以太网连接。

我通过将CAT5电缆升级为CAT7电缆(10米运行)解决了这个问题。

显然，旧的CAT5电缆无法处理我的ISP升级的速度(维珍媒体，英国)。新的CAT7电缆不仅停止了辍学，而且现在还允许自动配置从100 to /S到1000 to /S的速度。希望这能帮助任何想要修复“改变载波”错误的人。