Wrong Ethernet Port Settup at Debian Jessie

I have installed MX-Linux Debian based distro which is pretty much pure "debianoid". While installing KDE-plasma 5.x I got to update "testing" repo and everything worked nice and swell. Maybe it is not the cause of problem, just to say.

Now I'm gone with static IP address:

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
        address 192.168.1.151
        netmask 255.255.255.0
        gateway 192.168.1.1

...and stuff gone pretty much wierd. After editing /etc/network/interfaces and rebooting, system can't connect to Internet.

eth0 should be, cause at first I checked it with ifconfig. After that at /etc/network/interfaces switched to eth1 and system happily accepted Internet connection, but:

$ ifconfig 
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.6  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::ceea:171a:90e7:ba0b  prefixlen 64  scopeid 0x20<link>
        ether 74:d4:35:47:d4:d4  txqueuelen 1000  (Ethernet)
        RX packets 16696  bytes 12549408 (11.9 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 15737  bytes 1761287 (1.6 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

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 1  (Local Loopback)
        RX packets 1050  bytes 91770 (89.6 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1050  bytes 91770 (89.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

As you can see eth0 and eth1 is mixed and my IP address is not static. Another check:

$ sudo ifdown eth1 && sudo ifup eth1
ifdown: interface eth1 not configured
Cannot find device "eth1"
ifup: failed to bring up eth1

Please help.

Alex

Posted 2017-02-16T13:54:22.507

Reputation: 117

You are probably running NetworkManager by default, which manages eth0 automatically and correctly unless you mention eth0 in /etc/network/interfaces. So as soon as you renamed it to eth1, it worked, even though eth1 doesn't exist in the first place. Which means (a) your configuration is wrong, and (b) you don't really need it.

– dirkt – 2017-02-16T15:48:09.847

I know my configuration is wrong. And? – Alex – 2017-02-16T18:25:53.383

Is there any chance that the MAC address has changed, such as by cloning the machine? Debian is picky about the MAC address, and will rename the network device if the MAC address changes. – Charles Burge – 2017-02-16T19:23:35.080

In fact, this SSD was in different pc, but it worked (unlike Arch) well in this configuration. Then I reinstalled MX-Linux, but keeping home dir "intacta" as MX offered me in installation procedure. Is it possible to cause network confusion? – Alex – 2017-02-16T20:38:46.837

Wrong Ethernet Port Settup at Debian Jessie

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