[SOLVED] Created new Linux bridge and now lost access to node

[Bren_Chester]

Hello Everyone,

I'm hoping you all can help me figure out how to reverse the silly network change I made in the UI.
I was setting up a new Linux bridge and was going to create a separate network so I could have a lab which was isolated. Well, that was the plan.
Anyhow, created a new Linux bridge , put in a 10.0.0.1/24 IP range and saved the configuration and after the reboot, no UI access and not able to ping the IP.
I have IMPI access so at least I can log in that way and check\modify any of the configurations.
Some other extra parts are, I created networks which were labelled (Cyber-Net, Prod-Net, Lab-Net). From memory my original Linux bridge was running on vmbr0 and using the network interface enp1s0f0.
If I run nano /etc/network/interfaces, I I can see the vmbr0 interface is using the correct network card and is set with a static IP (see Interfaces screenshot).
When I check that network interface , I can see that its showing down but I'm unable to bring it back up\online. I have rebooted multiple times, physically reseated the network cables but I know its the change that I made is the issue.
I have tried resetting the interfaces config to using DHCP, restarted the network configuration etc but all with no joy.
When I check the network configuration, I can see no IP is being used.
This change is a big problem now for me as I have Truenas running on it with network shares which of course are not accessible. The rest of the LXC containers, I can rebuild.
I have scoured the net for the last 26 hours but nothing has been able to help me so I'm reaching out to you good folks for help
Has anyone any idea how I can get access back please? PS no backup to return too

 

[Bren_Chester]

All Network links showing down ?

 

[shanreich]

Anyhow, created a new Linux bridge , put in a 10.0.0.1/24 IP range and saved the configuration and after the reboot, no UI access and not able to ping the IP.
I have IMPI access so at least I can log in that way and check\modify any of the configurations.

Where did you configure the subnet? It isn't visible anywhere in the screenshots you posted.

enp1s0fX NICs are also showing NO-CARRIER which usually means there is no cable attached / the cable is broken. Are you sure that enp1s0fX were the cards you used before?

I think the best way forward would be to just configure the network on the physical NIC again, so you re-gain access to your node and then take it from there.

 

[Bren_Chester]

Where did you configure the subnet? It isn't visible anywhere in the screenshots you posted.

enp1s0fX NICs are also showing NO-CARRIER which usually means there is no cable attached / the cable is broken. Are you sure that enp1s0fX were the cards you used before?

I think the best way forward would be to just configure the network on the physical NIC again, so you re-gain access to your node and then take it from there.

Hey Shanreich,

The configuration for the subnet is with the slash 24 after the static IP : 192.168.0.206/24 .The 24 will give a subnet mask of 255.255.255.0 so 254 hosts.
This was always set like this, well until I couldn't access the web UI.
How do I re-configure the network on the physical NICs as I don't see a way through CLI or at least I don't know the commands to do so. I can't bring them up using the ifup .... It doesn't do anything. I did see where its showing no carrier but I find it strange that only after the reboot I can't access it. I can access the CLI through my iKVM (Proxmox running on Supermicro x10DRU-i+). I did reseat the network cables yesterday just in case but I will see if I can replace the cables also. It will mean having to take apart my cabinet to re-route the cables so will take some time.
Meanwhile, is there anywhere in the CLI I can check\update the NIC configuration?

 

[shanreich]

The configuration for the subnet is with the slash 24 after the static IP : 192.168.0.206/24 .The 24 will give a subnet mask of 255.255.255.0 so 254 hosts.
This was always set like this, well until I couldn't access the web UI.

Ah sorry I was confused since you mentioned 10.0.0.0/24 in the initial post

How do I re-configure the network on the physical NICs as I don't see a way through CLI or at least I don't know the commands to do so. I can't bring them up using the ifup .... It doesn't do anything. I did see where its showing no carrier but I find it strange that only after the reboot I can't access it. I can access the CLI through my iKVM (Proxmox running on Supermicro x10DRU-i+). I did reseat the network cables yesterday just in case but I will see if I can replace the cables also. It will mean having to take apart my cabinet to re-route the cables so will take some time.

You can always either try to reload the network configuration via ifreload -a . Alternatively you can use the ip command suite for changes to the running configuration without persisting them. Since the underlying interfaces all have NO-CARRIER you'd have to address that first, since otherwise no network configuration involving those NICs would work.

 

[Bren_Chester]

Something I just spotted now in the logs . Its showing the the bridge port is connected to the same interface so I would assume its causing a loop and not allowing access? Maybe?

 

[Bren_Chester]

Well networking 101, eh. It was the network cable in the end. Can't believe it as it only stopped working after the reboot. Weird. Anyways, replaced the cable and now the nic is showing up plus I added another for redundancy in case something like this happens again. Plus I will create a backup of the config and VM's etc in case I ever need to revert.
Thanks for your help shanreich in pointing me in the right direction

 

[Bren_Chester]

Just for giggles, here is the shot showing the 2 nics up and I now have access back to the UI. Yeah