Unable to access VM's over LAN

[Thomas M]

Hi,

I have a Dell R820 Server with the following network configuration.

auto lo
iface lo inet loopback

iface eno1 inet manual

auto vmbr0
iface vmbr0 inet static
address 172.20.100.140
netmask 255.255.255.0
gateway 172.20.100.2
bridge_ports eno1
bridge_stp off
bridge_fd 0

iface eno2 inet manual

auto vmbr1
iface vmbr1 inet manual
bridge-ports eno2
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094

iface eno3 inet manual

iface eno4 inet manual

vmbr0 is the Management Bridge as we can see and vmbr1 is the bridge for Public interface. The issue that we face is that the VM's connected to the bridge vmbr1 can communicate to the Internet perfectly. But the VM's that are connected to vmbr0 cannot communicate with the default route or the host and vice versa. Please let me know what I'm doing wrong and what should be done so that VM's are accessible over both Public and LAN networks.

 

[wolfgang]

Hi,
The Proxmox VE network settings are ok.
I guess it is the routing setting in the VM.

If you have two NICs with different networks you have to set up the routing correct.
The correct routes depend on the network environment and the use-case.

 

[Thomas M]

Hi,
The Proxmox VE network settings are ok.
I guess it is the routing setting in the VM.

If you have two NICs with different networks you have to set up the routing correct.
The correct routes depend on the network environment and the use-case.

Thanks for your time.

No I don't have 2 NIC in any of the VM's. I have only 5 VM's as of now.

- 2 Windows-2016 VM's connected to vmbr1 with Public IP and they work fine.

- 2 Linux and 1 Windows-10 that are supposed to be working in our LAN, connected to vmbr0. None of them can communicate with each other, default gateway (Zyxel ATP-100) or the host and vice versa.

FYI, O.S Firewall is disabled in all VM's.

 

[wolfgang]

Then the network config in the VM is not correct.
It there a VLAN involved in this setup?

A bridge is a primitive piece and works exactly the same way as a switch.
So if two VMs are on the same subnet it will deliver the packages. this has nothing to do with the IP on this bridge.
The IP (Proxmox VE management) is the same as the management IP of a switch.

 

[Thomas M]

Then the network config in the VM is not correct.
It there a VLAN involved in this setup?

A bridge is a primitive piece and works exactly the same way as a switch.
So if two VMs are on the same subnet it will deliver the packages. this has nothing to do with the IP on this bridge.
The IP (Proxmox VE management) is the same as the management IP of a switch.

I know that a Bridge is nothing more than a Virtual switch. Yes, there is an untagged VLAN involved to isolate our Internet from some other internal network stuff. But I don't think that is affecting this setup. Ideally with the above configuration LAN should work irrespective of what is on vmbr1 since both vmbr0 and vmbr1 are two distinct entities, right. Or am I missing something ??