Virtual machines without internet

[Servnet Mexico]

Good morning everyone. I currently have a node with approximately 40 virtual machines on a 5.3-11 version of proxmox. however when restarting the network service, all virtual machines were left without network. when trying to verify the status, they were all running, and even the same node had an internet connection but the virtual machines did not.

Do you know what this problem is due to? It should be noted that the server was telling me that the interfaces were up, but even so, none of the vm had a network.

 

[Hannes Laimer]

Hey,

since PVE 5.x is at its EOL since 2020-07 [1] I'd recommend upgrading your node [2], if the problem persists, just post again here.

[1] https://forum.proxmox.com/threads/proxmox-ve-support-lifecycle.35755/
[2] https://pve.proxmox.com/wiki/Upgrade_from_5.x_to_6.0

 

[Servnet Mexico]

ok, I understand, I will work on updating my equipment as soon as possible, however, I need to develop a report of what happened, I cannot find any log in which it indicates the failure, will you know the reason for the failure of this? or what exactly happened?

 

[Hannes Laimer]

This is a result of removing an underlying element of a stack. In this case, the Virtual Network builds on the existing Network on the Host. If this Network is removed, as is done during a restart, then the Virtual Network goes down and does not recover by itself.

 

[spirit]

proxmox plug dynamically the vm/ct interfaces into the bridge, when ct/vm start.
but this config is not present in /etc/network/interfaces.

so , if you do a "systemctl restart networking", it's remove the vmbr bridge, then recreate it, but can't replug the tap interfaces.

in proxmox6 , you can install ifupdown2 package, to do a reload "systemctl reload networking", and don't break network. (don't remember if ifupdown2 is already available in proxmox5)