Networking for guests stopped working after hours

[niak]

I'm running a Dedicated Server @ OVH with 2 guests. I'm trying Proxmox before buying and this issue is making me want to pull my hair out.

I generated MAC address, set in Proxmox GUI under Hardware (bridged, VirtIO), and then configured the /etc/network/interfaces inside the Guest (Ubuntu 16 & 18). It was PERFECT.

I had everything configured properly, guests running their own Failover IP's... I was able to ping domains and IP's... SSH into the boxes remotely and everything was flawless.

Now I'm unable to get any connection to the boxes and absolutely no config files have changed. I feel like I've faced this issue before, any suggestions?

 

[oguz]

hi,

* what versions do you have? (`pveversion -v`)
* did you do an update/upgrade anytime soon?
* check the config files of the guests once again (`qm config VMID` or `pct config CTID` if container)
* what about your ip address on the pve host? does `ip a` output match with /etc/hosts and /etc/network/interfaces ?

 

[niak]

hi,

* what versions do you have? (`pveversion -v`)
* did you do an update/upgrade anytime soon?
* check the config files of the guests once again (`qm config VMID` or `pct config CTID` if container)
* what about your ip address on the pve host? does `ip a` output match with /etc/hosts and /etc/network/interfaces ?

pveversion -v output

proxmox-ve: 5.4-1 (running kernel: 4.15.18-16-pve)
pve-manager: 5.4-7 (running version: 5.4-7/fc10404a)
pve-kernel-4.15: 5.4-4
pve-kernel-4.15.18-16-pve: 4.15.18-41
corosync: 2.4.4-pve1
criu: 2.11.1-1~bpo90
glusterfs-client: 3.8.8-1
ksm-control-daemon: 1.2-2
libjs-extjs: 6.0.1-2
libpve-access-control: 5.1-10
libpve-apiclient-perl: 2.0-5
libpve-common-perl: 5.0-52
libpve-guest-common-perl: 2.0-20
libpve-http-server-perl: 2.0-13
libpve-storage-perl: 5.0-43
libqb0: 1.0.3-1~bpo9
lvm2: 2.02.168-pve6
lxc-pve: 3.1.0-3
lxcfs: 3.0.3-pve1
novnc-pve: 1.0.0-3
proxmox-widget-toolkit: 1.0-28
pve-cluster: 5.0-37
pve-container: 2.0-39
pve-docs: 5.4-2
pve-edk2-firmware: 1.20190312-1
pve-firewall: 3.0-22
pve-firmware: 2.0-6
pve-ha-manager: 2.0-9
pve-i18n: 1.1-4
pve-libspice-server1: 0.14.1-2
pve-qemu-kvm: 3.0.1-4
pve-xtermjs: 3.12.0-1
qemu-server: 5.0-53
smartmontools: 6.5+svn4324-1
spiceterm: 3.0-5
vncterm: 1.5-3
zfsutils-linux: 0.7.13-pve1~bpo2

This server was installed today, it is OVH Dedi... I cannot wrap my head around this because both my VM's were working perfectly 6 hours ago, I have updated nothing since the initial install earlier this morning. Both were accessible inside guest (pinging google) and outside (sshing from my laptop to the guest VM). They are using Failover IP's, Proxmox was installed using the OVH template.

PVE Host internet is fine. 'ip a' returns my devices lo is inet 127.0.0.1/8, eth0, eth1, etc... vmbr0 shows my Host IP as well. I checked /etc/hosts on the host, it contains my Host IP and /etc/network/interfaces also contains my host IP. Anything specific you'd like me to paste? First time using Proxmox in an enterprise environment for my business and if I can get it working STABLY I would buy subscription immediately.

 

[oguz]

can you connect to your pve node through web gui?

what happens when you restart one of your vms? does networking start working then? btw, are they vm or ct?

edit:

can you post all the previously mentioned network related outputs without revealing your public ip fully?

 

[niak]

can you connect to your pve node through web gui?

what happens when you restart one of your vms? does networking start working then? btw, are they vm or ct?

edit:

can you post all the previously mentioned network related outputs without revealing your public ip fully?

Yup I can connect to the PVE node through the web GUI since as I mentioned the Host Internet is fine. I rebooted the Host and I rebooted the VM's multiple times however no internet on the guests. I'm testing inside the Web GUI and opening Console of the Guest. They are KVM VM's. Not containers.

 

[niak]

can you connect to your pve node through web gui?

what happens when you restart one of your vms? does networking start working then? btw, are they vm or ct?

edit:

can you post all the previously mentioned network related outputs without revealing your public ip fully?

Just updated with the network related outputs, let me know if you need any more.

 

[sumsum]

It May be a OVH Issue and Not related to Proxmox. A while back I experienced the Same Problem. 4 out 8 Linux VM‘s lost Connection. Before they were Running over month w/o problems.
My Solution, regenerate new MAC addresses for those failing VM‘s.
The OVH Network/Switch just lost the MAC address Information for some unknown reasons - which was confirmed by the OVH Support.

 

[niak]

It May be a OVH Issue and Not related to Proxmox. A while back I experienced the Same Problem. 4 out 8 Linux VM‘s lost Connection. Before they were Running over month w/o problems.
My Solution, regenerate new MAC addresses for those failing VM‘s.
The OVH Network/Switch just lost the MAC address Information for some unknown reasons - which was confirmed by the OVH Support.

It turns out it was a router issue on there end, many people were effected.