Linux bridge with two nic

Ting

Member
Oct 19, 2021
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Hi,

I have two nics in a proxmox, and each nic is on two different subnet. I created a Linux bridge to have both nics included, and assign this bridge to a vm. In this vm, I tried to ping a node in other subnet, but can not connect, not sure what did do wrong. The setup seems very straightforward, can not think what else I was missing.

Please point out to me what is correct way to connect two subnet together. Thanks in advance.
 
It is always helpful to post your network configuration: cat /etc/network/interfaces
 
Hi, Thanks for your reply,

here is network configuration:

auto vmbr7
iface vmbr7 inet static
address 10.0.10.200/24
bridge-ports eno4 enp3s0
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094



this is a bridge I created, and eno4 is on subnet 192.168.0.x/24, and enps3s0 is on subnet 10.0.10.x/24, I gave this bridge a ip address 10.0.10.200

and I assigned this bridge to a window vm, and this vm get a ip address from 192.168.0.x subnet, but I can not ping any nodes on subnet 10.0.10.x, I thought this bridge is a dump bridge, will route traffic between two subnet, not sure whether I need to setup any routing instructions.
 
enps3s0 is on subnet 10.0.10.x/24, I gave this bridge a ip address 10.0.10.200
Then there is a first probem. PVE host shouldn't have 2 IPs in the same subnet or this might cause routing problems.
 
I will do a test, but I thought by assigning ip to a bridge, only create a way for a node on subnet 10.0.10.x to access proxmox gui.
 
no, it did not resolve my issue. Sorry.

I removed this bridge's ip, applied the change, and reboot the vm, still no ping inside of this vm from subnet 192.168.0.x to other subnet 10.0.10.x
 
do you only have 1 physical switch ? (where are plugged the eno4 && enp3s0) ?

if yes, you'll have a network loop at layer2.


and you can't ping magically from 192.168.0.x to 10.0.10.x, you need a gateway somewhere in your network