Questions[ethernet](ubuntu)

I use static IP for my wired connection controlled via Network Manager.

ip link show enp4s0

2: enp4s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq state DOWN mode DEFAULT group default qlen 1000

NO-CARRIER would seem to indicate a driver issue as I'm posting this on the same PC by selecting the 4.18.0.17 prior kernel in grub. NetworkManager.service and avahi-daemon.service are both LOADED and ACTIVE.

But NetworkManager not happy as shown...

NetworkManager[1103]: <info>  [1555719488.0396] device (enp4s0): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
NetworkManager[1103]: <info>  [1555719488.0402] manager: NetworkManager state is now CONNECTED_LOCAL
NetworkManager[1103]: <info>  [1555719488.9594] manager: NetworkManager state is now CONNECTED_SITE
NetworkManager[1103]: <info>  [1555719488.9595] policy: set 'LaN' (enp4s0) as default for IPv4 routing and DNS
NetworkManager[1103]: <info>  [1555719488.9603] device (enp4s0): Activation: successful, device activated.
NetworkManager[1103]: <info>  [1555719488.9609] manager: NetworkManager state is now CONNECTED_GLOBAL
NetworkManager[1103]: <info>  [1555719488.9616] manager: startup complete
NetworkManager[1103]: <info>  [1555719495.0373] device (enp4s0): state change: activated -> unavailable (reason 'carrier-changed', sys-iface-state: 'managed')
NetworkManager[1103]: <info>  [1555719495.0583] manager: NetworkManager state is now DISCONNECTED
NetworkManager[1103]: <info>  [1555719505.6899] agent-manager: req[0x55c9724642a0, :1.63/org.freedesktop.nm-applet/1000]: agent registered

Could it be the wrong phy driver selected or Network Manager bug?

"ip link set enp4s0 up" doesn't help.

I have installed Ubuntu 18.04 on a Surface Book with dual boot, and I can't get the ethernet connection to work. Although the wifi connects, I keep getting the "activation of network connection failed" error for the ethernet.

sudo lshw -C network gives me:

  *-network                 
       description: Wireless interface
       product: 88W8897 [AVASTAR] 802.11ac Wireless
       vendor: Marvell Technology Group Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: wlp3s0
       version: 00
       serial: 98:5f:d3:45:f8:58
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=mwifiex_pcie ip=192.168.1.189 latency=0 multicast=yes wireless=IEEE 802.11
       resources: irq:133 memory:b9500000-b95fffff memory:b9400000-b94fffff
  *-network
       description: Ethernet interface
       physical id: 1
       logical name: enxc49dede69606
       serial: c4:9d:ed:e6:96:06
       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=r8152 driverversion=v1.09.9 duplex=half link=yes multicast=yes port=MII speed=10Mbit/s

But I suppose this is not near enough information to investigate. Please let me know what else is useful to know in this case, and I'll add that to the question.

PS: I saw this question, but I have all the updates installed, and I still can't connect, so this is not a duplicate.

UPDATE: Before turning off the computer, I turned off the cable connection in Settings. Today when I turned it on, the ethernet button is gone:

Running journalctl gives this: https://gist.github.com/sedulam/b37515fc90ab41a6d1c88a951baf11f6

ip ro gives this:

default via 192.168.1.254 dev wlp3s0 proto dhcp metric 600 
169.254.0.0/16 dev wlp3s0 scope link metric 1000 
192.168.1.0/24 dev wlp3s0 proto kernel scope link src 192.168.1.195 metric 600

systemctl gives: https://gist.github.com/sedulam/77d905dc3ecdf379a785b0694e23ed3e

ps aux | egrep wpa\|conn gives:

root      1037  0.0  0.0  45016  7504 ?        Ss   21:16   0:00 /sbin/wpa_supplicant -u -s -O /run/wpa_supplicant
pedro     3460  0.0  0.0  21536  1088 pts/0    S+   21:21   0:00 grep -E --color=auto wpa|conn

service --status-all gives: https://gist.github.com/sedulam/ae85b271a24aecdd3f04f920df2059e9

Surface Book model: Microsoft Surface Book 13.5 inch Touchscreen Laptop (Intel Core i7-6600U 2.6 GHz, 16 GB RAM, 512 GB SSD, NVIDIA 1 GB Integrated Graphics, Windows 10 Pro)

Upon bootup the network connection appears to be connected, for several reboots, I was shortly able to ping 8.8.8.8. However, I'm not longer able to do this. Then after logging in (<30 seconds) the network manager says the cable is disconnected. Unplugging and re-plugging the cable does not change this status.

The wireless connection is working.

I have previously used the wired connection in older versions of ubuntu (16.10 & 16.04) on this laptop, although I haven't tested them recently.

The network cable works with other computers.

The NIC device is a BCM5762.

Here is the output of ifconfig

    enp1s0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 40:b0:34:09:9a:c0  txqueuelen 1000  (Ethernet)
        RX packets 91  bytes 54152 (54.1 KB)
        RX errors 0  dropped 1  overruns 0  frame 0
        TX packets 146  bytes 32104 (32.1 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 36  
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 294  bytes 23870 (23.8 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 294  bytes 23870 (23.8 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.87.252.202  netmask 255.255.0.0  broadcast 10.87.255.255
        inet6 fe80::3260:ab36:9b89:9e58  prefixlen 64  scopeid 0x20<link>
        ether 7c:b0:c2:4e:13:d0  txqueuelen 1000  (Ethernet)
        RX packets 1247  bytes 1208923 (1.2 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 881  bytes 160559 (160.5 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Here is the output of lshw -C network

  *-network                 
       description: Ethernet interface
       product: NetXtreme BCM5762 Gigabit Ethernet PCIe
       vendor: Broadcom Limited
       physical id: 0
       bus info: pci@0000:01:00.0
       logical name: enp1s0
       version: 10
       serial: 40:b0:34:09:9a:c0
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm vpd msi msix pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.137 firmware=sb latency=0 link=no multicast=yes port=twisted pair
       resources: irq:36 memory:e0820000-e082ffff memory:e0810000-e081ffff memory:e0800000-e080ffff
  *-network
       description: Wireless interface
       product: Wireless 7265
       vendor: Intel Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlp2s0
       version: 59
       serial: 7c:b0:c2:4e:13:d0
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=4.15.0-23-generic firmware=29.1044073957.0 ip=10.87.252.202 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       resources: irq:47 memory:e0d00000-e0d01fff

I had been sharing my network connection through my computer (previously windows 10) with two other computers using usb-ethernet adaptors, and I can't get it to work now that my host computer is running Ubuntu 18.04.

The three wired connections appear in network settings as expected, but I don't know how to configure them to share internet and network.

Tutorials on the internet show a different network settings UI, with IPv4 Settings tab Method: "Shared to other computers". I don't have the option "Shared to other computers" and "Link-Local Only" does not seem to work.

How can I share one wired connection with two others?

is there a way to find out the PCI bus number of an Ethernet interface or vice versa. I am looking to write a Bash/Python script which gives some thing like

pci_address = some_function(eth0)

where pci_address is sys:bus:slot:function. How can these two elements be related to each other?