[TUTORIAL] Why network doesn't work on reboot

[ademirk]

I did install 4 pve's version 8.2.2 and notice a issue on installation config.
On install you can setup a netowork interface and the file /etc/network/interfaces became something like this:

# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

iface eno1 inet manual

iface eno2 inet manual

auto vmbr0
iface vmbr0 inet static
        address 172.16.0.2/16
        gateway 172.16.0.1
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

source /etc/network/interfaces.d/*

Your problem is that when you reboot, there is no interface automaticly loaded.
To solve this you just need to do is insert "auto" before your interface name, like this:

# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

auto eno1 #THIS LINE WILL SOLVE YOUR ISSUE
iface eno1 inet manual

auto eno2
iface eno2 inet manual

auto vmbr0
iface vmbr0 inet static
        address 172.16.0.2/16
        gateway 172.16.0.1
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0

source /etc/network/interfaces.d/*

 

[gfngfn256]

Thats rather odd. I've installed many times and have never had a problem. Never have I needed that auto you've placed before the NIC. I note you've also changed the address (.32 instead of .2), maybe you had a conflict with the address? Are you sure about that CIDR of /16? Assuming you are on a private local network, /16 will give you 65,024 hosts. Really?

 

[ademirk]

Thats rather odd. I've installed many times and have never had a problem. Never have I needed that auto you've placed before the NIC. I note you've also changed the address (.32 instead of .2), maybe you had a conflict with the address? Are you sure about that CIDR of /16? Assuming you are on a private local network, /16 will give you 65,024 hosts. Really?

no address was just a fail on copy/paste the solution.
I had this issue all the times I installed vpe, and found many forum threads with this issue, so I post this to help someone in future.

 

[gfngfn256]

I had this issue all the times I installed PVE, and found many forum threads with this issue, so I post this to help someone in future.

That is very kind & thoughtful of you.

Yes, there are many threads & forum posts on people's NWs not coming up after boot - but that does not mean their problem is the same as yours. (BTW mostly it is because of a NW change or the Linux system renaming the NICs).

Your solution, is perplexing to me, to say the least. Since usually all auto does is allow the NW interface to be brought up on system boot. This should be the case by default anyway. However if you make some special/additional config that has to be loaded during the system boot, then you probably need to add the auto to force this configuration at system boot. In your example you have not. For example take a look at this Proxmox
wiki, where only when a special config is added to the NIC do they add auto to it.

You must have some special HW/NW that is causing this to be required (maybe some power control that needs to force the NIC awake, IDK?).

I am replying, because I like to learn. I have never found any knowledge to be not useful.
Thanks again for sharing, Maybe tag prefix the thread-title with [TUTORIAL] or [SOLVED], (upper right hand corner under title).


P.S. Scouring the WWW, I found only one reddit (anonymous) comment suggesting your workaround.