IP is only on vmbr0, web UI no longer working

[jaxjexjox]

I have shut down my proxmox machine to recable my little homelab, I can't see it anymore.

I've tried a variety of cables, with no luck.
I know for a fact the network port is working because I can see the Intel vPro AMT console, I can ping that. (dedicated IP, same NIC)

https://i.imgur.com/YoWpH8B.png

I can sit at the machine, can't ping out any devices on my network, can't ping proxmox at all.
Any idea? I'm at a complete and utter loss.

 

[jaxjexjox]

Attempted more cables, switch 2 instead of switch 1, tried USB ethernet adapters (I had one in before) nope, no luck. Never seen anything like this.

 

[leesteken]

Both cabled network devices appear to be DOWN, while you would expect vmbr0 to bring one UP. What is the output of cat /etc/network/interfaces ?

 

[bbgeek17]

@leesteken is on the right track.
@jaxjexjox you probably had a kernel upgrade pending and your device names changed after reboot. Notice how you dont have an interface that is a member of vmbr0, ie:
6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 9000 qdisc noqueue master vmbr0 state UP group default qlen 1000
notice vmbr0^

So, review your interfaces file and fix the vmbr0 entry to point to the new name of the correct interface.

good luck

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[jaxjexjox]

I found a somewhat similar thread to my own :
https://forum.proxmox.com/threads/reset-all-networks-inteface.115162/

So I went along with this and identified that eno1 is my "real" ethernet adapter on the machine, by looking at mac addresses on my managed switch (phew!)
Despite the adapter being 'down' I simply changed a line in the following on a random guess.

************************************************
auto lo
iface lo inet loopback

iface enx0c3796451c2d inet manual

auto vmbr0
iface vmbr0 inet static
address 192.168.0.180/24
gateway 192.168.0.254
bridge-ports enx0c3796451c2d
bridge-stp off
bridge-fd 0

iface wlp0s20f3 inet manual

iface eno1 inet manual


source /etc/network/interfaces.d/*
************************************************



To:

************************************************
iface vmbr0 inet static
address 192.168.0.180/24
gateway 192.168.0.254
bridge-ports eno1
bridge-stp off
bridge-fd 0
************************************************


Lo and behold she's up, so I'd like to thank you all, I hope it helps someone else.

As to WHY this occurred, I'm going to speculate, when I first installed proxmox (2 weeks ago on this system) I built the machine with 2 network adapters attached, one of which was a USB one.
I reckon the system was working off the USB one, the whole time, that's my guess, hence the one it bound to.


Thanks again.

 

[jaxjexjox]

@leesteken is on the right track.
@jaxjexjox you probably had a kernel upgrade pending and your device names changed after reboot. Notice how you dont have an interface that is a member of vmbr0, ie:
6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 9000 qdisc noqueue master vmbr0 state UP group default qlen 1000
notice vmbr0^

So, review your interfaces file and fix the vmbr0 entry to point to the new name of the correct interface.

good luck

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

Upon actually reading your post properly, yes, you were bang on, really appreciate this and hope this subthread helps someone else.