Private Network between two VM's (Destination Host unreachable)

Bindos

Member
Mar 4, 2020
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Hello,

I have one pve Host with 4 Vm's. Each of the 4 Vm's has its own public IP. What I now want to configure is that for example two of the Vm's are connected to each other via a private network.

I did lots of research and configured following:

1.) At first i created a new bridge for the private network (vmbr1)
2.) I configured the bridge on the pve Host like this:
auto vmbr1
iface vmbr1 inet static
address 10.0.0.1
netmask 255.255.255.0
bridge-ports none
bridge-stp off
bridge-fd 0
3.) After that I added the vmbr1 bridge to the Vms via the HardwareTab
4.) I configured the bridge on the VM's
auto vmbr1
iface vmbr1 inet static
address 10.0.0.3
netmask 255.255.255.0
bridge_ports none
bridge_stp off
bridge_fd 0
One of my Vms is a Windows VM. On this machine I configured the second Virtio Network Adapter with the following settings:
IP: 10.0.0.2
Netmask 255.255.255.0

I am able to ping the windows vm from the pve host and I am also able to ping the pve host from the windows vm wit hthe private IPs (10.0.0.1&10.0.0.2) but I am not able to ping the linux Vm. When i try to ping it i get the following errors:
Pinging 10.0.0.3 with 32 bytes of data:
Reply from 213.198.77.85: Destination net unreachable.
Reply from 213.198.77.85: Destination net unreachable.
Reply from 213.198.77.85: Destination net unreachable.
Reply from 213.198.77.85: Destination net unreachable.
I also dont know where this IP "213.198.77.85" is coming from... It has nothing to do with the IP Subnet I am using for my public IP configuration.

So there has to be a mistake with the linux vm configuration. But i dont know whats wrong....
ifconfig show me this:
vmbr1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.0.3 netmask 255.255.255.0 broadcast 10.0.0.255
inet6 fe80::4429:33ff:fe58:dd6c prefixlen 64 scopeid 0x20<link>
ether 46:29:33:58:dd:6c txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 22 bytes 1384 (1.3 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

On the pve Host ifconfig shows this:
vmbr1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 10.0.0.1 netmask 255.255.255.0 broadcast 10.0.0.255
inet6 fe80::301d:6bff:fe43:e4d4 prefixlen 64 scopeid 0x20<link>
ether be:e9:b5:a0:02:5f txqueuelen 1000 (Ethernet)
RX packets 221 bytes 16430 (16.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 76 bytes 5396 (5.2 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

I just cant figure out what I have done wrong....

I hope someone can help me. Btw the public ips are working fine.

Thanks in advance.
 
2.) I configured the bridge on the pve Host like this:
auto vmbr1
iface vmbr1 inet static
address 10.0.0.1
netmask 255.255.255.0
bridge-ports none
bridge-stp off
bridge-fd 0

you don't need ip adress on vmbr1 on the host (until you want that vm access to proxmox ip from vmbr1)

4.) I configured the bridge on the VM's
auto vmbr1
iface vmbr1 inet static
address 10.0.0.3
netmask 255.255.255.0
bridge_ports none
bridge_stp off
bridge_fd 0
why do you create a bridge inside the vm ? (and it'll can't communicate to outside, as "bridge_ports none" )
you simply need to defined an ethx in your vm with the ip address
 
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