I messed things up in /etc/network/interfaces and now my onboard ethernet adapter (eth0) won't show up

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fruitkiller
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I messed things up in /etc/network/interfaces and now my onboard ethernet adapter (eth0) won't show up

Post by fruitkiller » Tue May 22, 2018 5:43 pm

Only my old pci 10/100 shows up at boot and I'm not sure what it is that I've done wrong. Which isn't convenient because I have 350mbps/350mbps FTTH and this old pci ethernet card is saving my ass for now, that's why I keep it, among other reasons. I have to bring up eth0 with sudo ifconfig eth0 up and even if it will show if I do ifconfig,the 2 arrows of the network-manager disappear when I now plug the cable into that much faster 10/100/1000 adapter from my motherboard.

Only happened after I had the computer completely freeze on me, which is very rare, when I brought up jdownloader2 which I hadn't in a long time and it froze as it was "rebuilding cache" or such.

Here's what my /etc/network/interfaces file look like...I've only been playing with it to have the mac addresses being changed at boot, when I attempted to have it done for eth0, it seemed to work, but I had not rebooted in a long time, a month or so

Code: Select all

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).


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


# Network interfaces

allow-hotplug eth0
iface eth0 inet dhcp
  hwaddress ether xx:xx:xx:xx:xx:xx

allow-hotplug eth1
iface eth1 inet dhcp
  hwaddress ether xx:xx:xx:xx:xx:xx 
Originally allow-hotplug was not on eth1, but now if I don't add it, I have no way to get online, I forgot how to restart the network in a more efficient fashion than with "sudo /etc/init.d/networking restart" which I think is not ideal and I have other tools installed to restart fully, as in a dns restart. I'm not sure what to do, I don't know why my important (fast as my connection allows) adapter isn't up by default all of a sudden and even if I bring it up, a connection will simply not happen even if I switch the cable to it.

At least I figured out how to get back online. Got no wifi running here, disabled entirely on the router and my mobo doesn't even have a wifi adapter anyways, holes were drilled in too many places in this house and annoyingly hard to put up and long ethernet cables go to all the rooms in this place so there's no bothering with it. Anyway that's not my main problem here. I know the onboard ethernet adapter isn't broken as I can conjure it, plus a green light and pulsing happens when I get it connected on the plug, so this is just a result of my messing around. Sigh, feels like a rookie mistake, I'm sure I knew how to fix this before and just forgot after all those years.

fruitkiller
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Re: I messed things up in /etc/network/interfaces and now my onboard ethernet adapter (eth0) won't show up

Post by fruitkiller » Tue May 22, 2018 9:32 pm

Looks worse than I thought....when the desktop froze...it seems like it has burned in a new mac address! I don't remember by heart what the AsusTek Inc. onboard adapter mac address was and since it's a unique thing...macchanger --list=Asus doesn't help, I would remember if I saw the the three last couple of digits that were the right ones, I would remember then, I imagine I could inscribe anything with it and maybe get it to work again?

It doesn't even boot up with the forced mac change in the file I showed in the previous post, it's now a unknown adapter, which does not connect. I don't understand how that could have happened, I remember entering this one using hw ether :address: in the command line a few minutes before the whole snafu, but I can't get back my old real mac address burned in (seemingly replaced forever?!?) with this non-working currently mac address, it refuses to work, and I'm down on my main desktop to 100mbps/100mbps when I pay for 350/350...this is the weirdest thing I've ever seen. If I could just see a list of mac addresses for the onboard adapter that's on my asus motherboard, maybe I could fix things, but it seems like that strange freeze burnt in that fake mac address...which spooks me. And now I notice how slower things are, even at 100/100. I can't believe this, I even installed something called ethtool that would be able to bring back supposedly the real mac address but, nope, it says the fake one I entered before the whole system froze is the real one...

fruitkiller
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Posts: 384
Joined: Tue Aug 05, 2014 7:52 pm

Re: I messed things up in /etc/network/interfaces and now my onboard ethernet adapter (eth0) won't show up

Post by fruitkiller » Wed May 23, 2018 2:25 pm

Just in case someone is interested...I got eth0 to work again doing this :

"sudo nano /etc/NetworkManager/NetworkManager.conf"

And changed ifupdown=false to true, so now it was managed by the network-manager. But still, whatever caused the freezing of that desktop yesterday...it permanently burnt in a fake mac address I gave it through that way hwaddress ether 00:00:00:00:00:00 (not giving it). So once that was changed, and macchanger used to give it some known company fake mac address instead of the now burned in (unknown), everything is fine.

It's strange how eth1, the added pci ethernet card responds to the change made in the interfaces file, but not eth0, hence why I was trying to change it through some other way, at boot, it takes the mac address in the interfaces file as if it was its real one, if I remove the lines, on boot it will show up its real D-Link mac add, but not the onboard adapter (eth0), seems like it lost its identity for good, although it is recognized by network-manager as the right kind of device, Realtek Network Adapater blah blah blah, I'm not sure if it said that before, I know identifying it with macchanger would say it was an AsusTek adapter. But no more.

If anybody can analyse this situation and give me their 2 cents I'd appreciate it very much!

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