CentOS - Feb 2017 - Centos7: Intel nuc/Linksys usb-ethernet

Hello All, 

I'm installing some DIY routers, composed of Intel nuc's ,Linksys
usb-ethernet adapters and Centos7

On most machines I just plug in the usb device, install Centos7 and everything
works.
But on this one machine the network interface doesn't work. 

After installing ip addr shows: 

[root at clgmol ~]# ip addr 
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 
inet 127.0.0.1/8 scope host lo 
valid_lft forever preferred_lft forever 
inet6 ::1/128 scope host 
valid_lft forever preferred_lft forever 
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
state UP qlen 1000
link/ether f4:4d:30:64:21:bb brd ff:ff:ff:ff:ff:ff 
inet 192.168.80.189/25 brd 192.168.80.255 scope global dynamic enp3s0 
valid_lft 431sec preferred_lft 431sec 
inet6 fe80::f64d:30ff:fe64:21bb/64 scope link 
valid_lft forever preferred_lft forever 
3: wlp2s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000 
link/ether b8:81:98:9f:8f:1c brd ff:ff:ff:ff:ff:ff 
4: enp0s20u3c2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen
1000
link/ether 14:91:82:3b:7b:b9 brd ff:ff:ff:ff:ff:ff 

[root at clgmol ~]# dmesg | tail -n15 
[ 10.582462] Bluetooth: hci0: Intel device is already patched. patch num: 25 
[ 10.770781] usb 2-3: new SuperSpeed USB device number 3 using xhci_hcd 
[ 10.782704] usb 2-3: New USB device found, idVendor=13b1, idProduct=0041 
[ 10.782728] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=6 
[ 10.782745] usb 2-3: Product: Linksys USB3GIGV1 
[ 10.782759] usb 2-3: Manufacturer: Linksys 
[ 10.782772] usb 2-3: SerialNumber: 000001000000 
[ 10.787858] cdc_ether 2-3:2.0 eth0: register 'cdc_ether' at
usb-0000:00:14.0-3, CDC Ethernet Device, 14:91:82:3b:7b:b9
[ 14.140292] nf_conntrack version 0.5.0 (16384 buckets, 65536 max) 
[ 14.175958] Netfilter messages via NETLINK v0.30. 
[ 14.178428] ctnetlink v0.93: registering with nfnetlink. 
[ 14.350689] ipt_ULOG: ULOG: fail to register logger. 
[ 15.192593] ipt_ULOG: ULOG: fail to register logger. 

I create /etc/sysconfig/network-scripts/ifcfg-enp0s20u3c2 using the hardware
address from ip addr en uuid created with uuidgen but I don't understand why
it's not created on install:

TYPE=Ethernet 
BOOTPROTO=static 
DEFROUTE=yes 
IPV4_FAILURE_FATAL=no 
IPV6INIT=no 
IPV6_AUTOCONF=yes 
IPV6_DEFROUTE=yes 
IPV6_PEERDNS=yes 
IPV6_PEERROUTES=yes 
IPV6_FAILURE_FATAL=no 
IPV6_ADDR_GEN_MODE=stable-privacy 
NAME=enp0s20u3c2 
UUID=a728528c-0be7-49bc-9478-05743a285a7d 
DEVICE=enp0s20u3c2 
ONBOOT=yes 
PEERDNS=yes 
PEERROUTES=yes 
NM_CONTROLLED=no 
HWADDR=14:91:82:3b:7b:b9 
IPADDR=192.168.70.1 
NETMASK=255.255.255.0 

Next I cannot launch the network: 

[root at clgmol ~]# systemctl status network 
? network.service - LSB: Bring up/down networking 
Loaded: loaded (/etc/rc.d/init.d/network; bad; vendor preset: disabled) 
Active: failed (Result: exit-code) since di 2017-02-21 20:57:56 CET; 15s ago 
Docs: man:systemd-sysv-generator(8) 
Process: 2638 ExecStart=/etc/rc.d/init.d/network start (code=exited,
status=1/FAILURE)
CGroup: /system.slice/network.service 
??1076 /sbin/dhclient -H clgmol -1 -q -lf
/var/lib/dhclient/dhclient-13b56b89-7b1d-42fa-aeb7-af96a38102ce-enp3s0.lease -pf
/var/run/dhclient-enp3s0.pid en...

feb 21 20:57:56 clgmol.router network[2638]: RTNETLINK answers: File exists 
feb 21 20:57:56 clgmol.router network[2638]: RTNETLINK answers: File exists 
feb 21 20:57:56 clgmol.router network[2638]: RTNETLINK answers: File exists 
feb 21 20:57:56 clgmol.router network[2638]: RTNETLINK answers: File exists 
feb 21 20:57:56 clgmol.router network[2638]: RTNETLINK answers: File exists 
feb 21 20:57:56 clgmol.router network[2638]: RTNETLINK answers: File exists 
feb 21 20:57:56 clgmol.router systemd[1]: network.service: control process
exited, code=exited status=1
feb 21 20:57:56 clgmol.router systemd[1]: Failed to start LSB: Bring up/down
networking.
feb 21 20:57:56 clgmol.router systemd[1]: Unit network.service entered failed
state.
feb 21 20:57:56 clgmol.router systemd[1]: network.service failed. 

[root at clgmol ~]# ifup enp0s20u3c2 
arping: recvfrom: Netwerk ligt plat 
RTNETLINK answers: Network is down 

I disabled NetworkManager 
I tried with another Linksys device and I reinstalled and started over. 

Why does it work with other devices and not with this one? 
Many thanks for any advise. 

Greetings, J

Hi,

Suggestions inline.

On 21-02-17 21:03, johan.vermeulen7 at telenet.be wrote:
[snip]
>
> Next I cannot launch the network:
>
> [root at clgmol ~]# systemctl status network
> ? network.service - LSB: Bring up/down networking
> Loaded: loaded (/etc/rc.d/init.d/network; bad; vendor preset: disabled)
Your network.service is still disabled so try enabling it:

# systemctl stop NetworkManager.service
# systemctl disable NetworkManager.service
# systemctl enable network.service
# systemctl start network.service
# systemctl status network.service

If the network.service fails, see below, review, fix and try again.
> Active: failed (Result: exit-code) since di 2017-02-21 20:57:56 CET; 15s
ago
> Docs: man:systemd-sysv-generator(8)
> Process: 2638 ExecStart=/etc/rc.d/init.d/network start (code=exited,
status=1/FAILURE)
> CGroup: /system.slice/network.service
> ??1076 /sbin/dhclient -H clgmol -1 -q -lf
/var/lib/dhclient/dhclient-13b56b89-7b1d-42fa-aeb7-af96a38102ce-enp3s0.lease -pf
/var/run/dhclient-enp3s0.pid en...
>
> feb 21 20:57:56 clgmol.router network[2638]: RTNETLINK answers: File exists
[snip]

IIRC make dhclient release the current lease and stop the running DHCP 
client, then remove any lingering leases files:

# dhclient -r
# rm -v -i /var/lib/dhclient/dhclient*.lease*

Also remove any /etc/sysconfig/network-scripts/ifcfg-* files created by 
NetworkManager that might interfere with your ifcfg-enp0s20u3c2 and the 
network.service. Then try to start the network.service again.

HTH,
Patrick