Proxmox can connect to network, but VMs cannot

[sugarleaves]

Hello,

Proxmox newbie here. I was previously running three VMs in proxmox, all Ubuntu Server. I stopped my server to reconfigure a hardware raid drive, then started Proxmox again. Everything was fine; Proxmox was able to recognize the new disk, and I was able to add it as LVM storage and attach it to my VMs as hard disks in their hardware tabs.
Here's where things got bad.
I ended up running "Move Storage" on my VMs, so their storage was on the new disk. The VMs start OK, but for some reason, they cannot connect to the network. Running a 'ping 192.168.0.110` (my DHCP/DNS server) returns a "connect: Network is unreachable" error.I haven't changed anything about the configuration of proxmox or these VMs, other than moving storage.

I even tried creating a new VM (also Ubuntu server), and during installation for the network configuration, it is unable to get an IP address (previously when installing, I was able to configure the network just fine).

This is driving me crazy, and my network drives with all my information are completely isolated now (I can still connect to the VM in Proxmox, but not via network/SSH)! Has anyone experienced something like this before? Any help is greatly appreciated!

 

[sugarleaves]

I ended up re-installing Proxmox on a spare SD card and tried to install a ubuntu server VM on that. When that failed to get an IP, that led me to check my external network hardware which I reset. Resetting the network hardware seems to have solved the issue.

 

[cdjambov]

I am running pfSense (separate box) and one node of proxmox 5.latest and after power outage I had the same issue. After fiddling around quite a bit I turned off the firewall of the node > DataCenter\<nodename>\Firewall\Options\Firewall and "Bob is your uncle" as they say down below.