What is the purpose of the lxdbr0 bridge has a ip address? it is just a l2 network device

LXD
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7
  • i have a preliminary understanding of ovn & ovs.
  • i 'm building one private cloud based on lxd.

and i have another related question.
i have a ip address pool for external network(for example, 192.168.5.50~192.168.5.100)

    1. ip addr of eth0 on lxdserver1 is 192.168.5.50
    1. ip addr of eth0 on lxdserver2 is 192.168.5.51
    1. ip addr of eth0 on lxdserver3 is 192.168.5.52
    1. ip range 192.168.5.53-192.168.5.100 is for vswitch(I want my VPC to have an independent external IP address)

i have already knowed that lxdbr0 could be a uplink network,
so i can create some ovn networks and set their parent network to lxdbr0.
anyway, the traffic of any instance in these ovn networks will route to lxdbr0 by snat and dnat.
but these openVSwitch doesn’t have a external ip address.

It can be seen from the official user manual of LXD, It seems that LXD wants users to pay more attention to the private network level, Instead of configuring for routers. So in the lxd restapi, you can see that the security rule group is configured based on the network, but not based on a vpc.
I don’t know how to plan the use of external IP pools in LXD.

I know that the more routes, the greater the network communication overhead.
So when I create too many instance in my ovn network and which parent is lxdbr0,
The overall network performance maybe poor.

but now what i want to ask is ,

  1. to make full use of external ip addr pool, how should I create an ovn network？
  2. Try not to treat lxdbr0 as an uplink network, and the network performance will be better. Am I right?
  3. I didn’t find the lxd rest API about network device , how can i list all network device but not network in lxd?
    (just like lxc vpc list, lxc ovs list),I will need to configure IPSec and GRE for VPC in the future
  4. In the figure below, i think there is a vswitch in the background, and it has a nic in ovn network ovn1 and ip is 10.49.23.1, the vswitch also has a nic in bridge network lxdbr0 and ip maybe 10.241.203.240, this depends on the following configuration, am i right?
    ipv4.ovn.ranges=10.241.203.200-10.241.203.254
  5. how can i get the ip of vswitch in external network？i have config the ipv4.ovn.ranges but I don’t know which one is occupied.
  6. Can i create a virtual switch with an public external network IP address？(doesn’t treat the bridge network as a parent) Do you think it’s good to do this?

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I ask a lot of questions at one go，
I’m really interested in learning LXD/LXC,
Looking forward to your reply.