VMs bridge seems not to be working

[oscarbaselga]

Hi there,

PVE version
v8.3.0

Short description
VMs are not able to reach the gateway of the LAN.

Detailed description
The host (Asus PN51) can reach the gateway of the LAN via ping (and therefore it has Internet access), but VMs (Ubuntu server 22.04) cannot.
I suspect that it must be a problem related to the configuration of the network bridge between the VMs and the host, but I do not find the error.
The network configuration of my host is the following:




And the hardware configuration of a VM:



I have no firewall rules configured.

Bests,
Oscar

 

[shanreich]

How does the network config inside the VMs look like? (ip a; ip r)

 

[oscarbaselga]

How does the network config inside the VMs look like? (ip a; ip r)

I have configured a static IP address, that is why it is allocated in ens18.



However, if that configuration is removed, it does not allocate any IP address (I assume because the VM cannot reach the DHCP server of the LAN's gateway).



Regards,
Oscar

 

[shanreich]

When trying to get a DHCP lease, what is the output of dhclient -v ?

 

[oscarbaselga]

When trying to get a DHCP lease, what is the output of dhclient -v ?

It never receives a DHCPOFFER:

 

[shanreich]

Does pinging the gateway work with the static IP? Do the DHCPOFFER / packets reach the gateway? If yes, do offers go out? Is there any firewall involved there?

 

[oscarbaselga]

Does pinging the gateway work with the static IP? Do the DHCPOFFER / packets reach the gateway? If yes, do offers go out? Is there any firewall involved there?

• No, VMs cannot even ping the gateway with the static IP configuration.
• I have no permissions to access the gateway, so I cannot check that.
• There are no firewalls.

Anyway, I wanted to ensure that the problem was not my fault (a configuration error in proxmox), so I am going to contact my network administrator to find a solution.

Thanks @shanreich for your support,
Oscar

 

[shanreich]

Yes, the setup seems correct - are you using a host like Hetzner? It can be that you need to explicitly register additional MAC-addresses for that port.

 

[oscarbaselga]

Yes, the setup seems correct - are you using a host like Hetzner? It can be that you need to explicitly register additional MAC-addresses for that port.

I do not know, I am going to ask my administrator

Regards,
Oscar