Trouble with ethernet connection, 18.04

**wildmanne39** · October 11th, 2018

Your welcome and looks good!

**NM5TF** · October 12th, 2018

what is the output of

Code:

inxi -N

almost sounds like a hardware failure starting to happen...

tommy

**James_Creasy** · October 15th, 2018

Code:

$ inxi -N
Network:   Card: Marvell 88W8897 [AVASTAR] 802.11ac Wireless driver: mwifiex_pcie

I've discovered that sometimes I can get the ethernet interface to show up on 'ip link' by disconnecting the dock connector from the laptop and reconnecting it. Not consistent though. I've repro'd this on two different dock connectors, one at home and one at the office.

**heynnema** · October 16th, 2018

If you're running on a SSD, you run the risk of things booting faster than the network is coming online and then you'll need to modify the following file: `/etc/systemd/system/network-online.target.wants/NetworkManager-wait-online.service`

Code:

[Unit]
Description=Network Manager Wait Online
Documentation=man:nm-online(1)
Requires=NetworkManager.service
After=NetworkManager.service
Before=network-online.target

[Service]
Type=oneshot
ExecStart=/usr/bin/nm-online -s -q --timeout=60
RemainAfterExit=yes

[Install]
WantedBy=network-online.target

and change the timeout from `30` to `60`.

update: this doesn't fix the problem... sigh... a newer kernel does

**James_Creasy** · October 17th, 2018

I changed the timeout to 60 as suggested, the ethernet interface is still not visible:

Code:

$ inxi -N
Network:   Card: Marvell 88W8897 [AVASTAR] 802.11ac Wireless
           driver: mwifiex_pcie

I then disconnected and reconnected the dock connector on the laptop, now 'ip link' shows the ethernet interface:

Code:

$ ip link1: 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: wlp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DORMANT group default qlen 1000
    link/ether c4:9d:ed:a8:15:51 brd ff:ff:ff:ff:ff:ff
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default 
    link/ether 02:42:41:4e:0f:80 brd ff:ff:ff:ff:ff:ff
4: enxbc8385f72540: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN mode DEFAULT group default qlen 1000
    link/ether bc:83:85:f7:25:40 brd ff:ff:ff:ff:ff:ff

I added this new id to the /etc/network/interfaces file and ran 'ifup':

Code:

$ sudo ifup enxbc8385f72540
Internet Systems Consortium DHCP Client 4.3.5
Copyright 2004-2016 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/


Listening on LPF/enxbc8385f72540/bc:83:85:f7:25:40
Sending on   LPF/enxbc8385f72540/bc:83:85:f7:25:40
Sending on   Socket/fallback
DHCPDISCOVER on enxbc8385f72540 to 255.255.255.255 port 67 interval 3 (xid=0x2b48a007)
DHCPDISCOVER on enxbc8385f72540 to 255.255.255.255 port 67 interval 4 (xid=0x2b48a007)
<snipped more DHCPDISCOVER...>

No DHCPOFFERS received.
No working leases in persistent database - sleeping.

Not yet working.

**heynnema** · October 22nd, 2018

Turns out that my previous post about changing a timeout value doesn't fix the problem. I've been banging my head against the wall with this problem for weeks. I had checked everything. NetworkManager. Netplan. Now... here it comes... this problem originally showed up in kernel -29, and was still present with kernel -36. I just upgraded from 18.04 to 18.10, and I haven't seen the problem again! Kernel problem.