networking in lxc not coming up after debian v7 to v8 update

[hk@]

Here is what we tried:
moved an openvz container backup to a new proxmox, restores fine; networking also coming.
updated debian v7 within the container to v8
now after every reboot of this container the "eth0" within the container is gone.
after manually "/etc/init.d/networking restart" eth0 comes backup and routes get installed.

would be interested in any pointer on how to find this issue.

 

[H4R0]

The interface naming convention got changed sometime.

Instead of eth0.. its enp1s0 etc. depends on mac.

I assume thats your problem.


You probably have to adjust /etc/network/interfaces with the new interface name

What does "ip a" within the cointainer output ?

 

[hk@]

The interface naming convention got changed sometime.

Instead of eth0.. its enp1s0 etc. depends on mac.

I assume thats your problem.


You probably have to adjust /etc/network/interfaces with the new interface name

What does "ip a" within the cointainer output ?

well, eth0 is in fact within the container basically whatever name you'd like to name it.

interfaces are adjusted correctly - otherwise a networking restart would not work either.

after startup "ip a" only shows localhost, after networking restart all is well.

I'm more looking for a way to find the trouble during startup of the container as we believe it's more like a startup-issue not a "networking does not work at all"

thx!

 

[LnxBil]

updated debian v7 within the container to v8

Debian Jessie is also quite old, why not update to Debian 10 Buster and try again with it?

after manually "/etc/init.d/networking restart" eth0 comes backup and routes get installed.

That could imply that it is not run on startup. Please try to get the console output (setting console to /dev/console) and see if there are any errors.

 

[hk@]

well, updating something that doesn't work is usually not our way of solving an issue

so - in the end we found the culprit:
"journalctl -b" is our friend.
there we saw " networking[60]: ifup: pre-up script failed "
the reason behind: we startup firewall-scripts before the interface goes up; there we also started fail2ban, but this somehow exits with an error, we removed therefore fail2ban form the pre-up sequence and now networking gets started ok;
though we don't see the reason why fail2ban fails (no pun intended) but for now we do not debug fail2ban to get into the details of this.

 

[LnxBil]

well, updating something that doesn't work is usually not our way of solving an issue

No? That is the default answer every paid support gave me in the last 20 years. "Update to the newest version, try to replicate and report back"