Node has lost network connectivity after adding VLAN interface

[Pandez]

I was messing with one of the nodes on my proxmox cluster and experimenting with putting the management interface/GUI on it's own VLAN, and in the process managed to completely kill the network connectivity on the node even after undoing all my changes. I'll try to explain in a series of steps.

Originally, my /etc/network/interfaces file looked something like this:

auto lo
iface lo inet loopback

iface enp8s0 inet manual

auto vmbr0
iface vmbr0 inet static
    address 192.168.0.116/24
    gateway 192.168.0.1
    bridge-ports enp5s0
    bridge-stp off
    bridge-fd 0
    bridge-vlan-aware yes
    bridge-vids 2-4092

I have an existing VLAN 10 on the switch this node is connected to, so I update the file to read like this:

auto lo
iface lo inet loopback

iface enp8s0 inet manual

auto vmbr0.10
iface vmbr0.100 inet static
    address 192.168.0.116/24
    gateway 192.168.0.1

auto vmbr0
iface vmbr0 inet static 
    bridge-ports enp5s0
    bridge-stp off
    bridge-fd 0
    bridge-vlan-aware yes
    bridge-vids 2-4092

This works! I connect the switch to a port that accepts tagged traffic for VLAN 10 and can access it from other ports that belong to the same VLAN. So far, so good.

Other devices use VLAN 10 however, and I want my management interface to be on it's own dedicated VLAN. I set up VLAN 100 on two ports for the switch (one connected to the node, the other to my main router where my PC is connected). Then I add VLAN 100 as an interface in the proxmox GUI. I haven't re-assigned the IP to it yet and while the VLAN exists in the switch no traffic should be getting sent on it yet as the PVIDs are all still set for VLAN 10.

Regardless, as soon as I hit the apply configuration on button in the Proxmox GUI the node's network connectivity goes down and stays down. I have to connect a monitor to it so I can access the node directly and undo all my changes to /etc/network/interfaces until it looks like it did originally. Even so, I can't connect to or ping the node regardless of if it's connected to the switch, my main router (which has no VLANs at all), or with a direct connection between the node and an end terminal like a laptop.

Here's a snapshot of the output from running ip addr on the node: https://imgur.com/a/aa2iXlg

Two things I notice are that the NIC and vmbr0 both show a perpetual state of DOWN even though the physical link is good, and the MAC addresses don't match. I am not sure if they did before, but in my other still-working node these equivalent values are the same. I'm not sure how that would've changed from what I did or how to make the MACs match, if that's the problem. Advice or other suggestions would be appreciated.

 

[vesalius]

Might simply be mistypes or copy paste errors, but in case not:

1. vmbr0 uses bridge-ports enp5s0 but there is no iface enp5s0 inet manual line.
2. You do have a iface enp8s0 inet manual line, but nothing else is using enp8s0
3. Not sure which you want to actually use here, but the vlan needs to be consistent, either vmbr0.10 or vmbr0.100 not both in same section.

   1. auto vmbr0.10
      iface vmbr0.100 inet static

 

[Pandez]

Might simply be mistypes or copy paste errors, but in case not:

1. vmbr0 uses bridge-ports enp5s0 but there is no iface enp5s0 inet manual line.
2. You do have a iface enp8s0 inet manual line, but nothing else is using enp8s0
3. Not sure which you want to actually use here, but the vlan needs to be consistent, either vmbr0.10 or vmbr0.100 not both in same section.

   1. auto vmbr0.10
      iface vmbr0.100 inet static

What I wrote in the thread where copypaste errors since I pasted the interfaces text from my other node and didn't correctly adjust everything because I wasn't paying sufficient attention (the VLAN part is just a straight error, though).

However, when looking at the my non-working node again, I noticed that bridge-ports had actually been changed to none somehow. I changed the value to enp8s0 and rebooted, now everything works correctly. Unsure how that value got changed in the first place, though!