Purpose of the internal interfaces

[mipsH]

Hello.

I just want to understand the standard OpenvSwitch/Linux native interfaces used in Proxmox VE, when using SDN/VNets:
VNetINT is name of my VNet

Looking at the OpenvSwitch level:

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ovs-vsctl list interface | egrep "^name|^status|^type"
name : vmbr0 --> This is a Bridge
status : {driver_name=openvswitch}
type : internal
name : ln_VNetINT --> what is this ?
status : {driver_name=openvswitch}
type : internal
name : enp0s3 --> This is my NIC (in this case VirtIO since Proxmox is started as VM)
status : {driver_name=virtio_net, driver_version="1.0.0", firmware_version=""}
type : ""

---

Next to see the OVS bridge:

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ovs-vsctl list-ports vmbr0
enp0s3
ln_VNetINT

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So we can conclude:
ln_VNetINT <--> (Bridge) vmbr0 <--> (NIC) enp0s3


Looking at the Linux bridge level, we can see:

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brctl show
bridge name bridge id STP enabled interfaces
VNetINT 8000.2ef33389af83 no ln_VNetINT

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So from Linux side i can understand that:
(Bridge ) VNetINT --> (Interface) ln_VNetINT


So in summary:

[OVS] [Linux]

(NIC) enp0s3 <--> (Bridge) vmbr0 <---------> ln_VNetINT <==============> (Bridge) VNetINT
| | |
(to TAP or VETH to VMs) ? ?

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---

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But when started for example LXC container Nr. 100; with two interfaces we have:

brctl show
bridge name bridge id STP enabled interfaces
VNetINT 8000.2ef33389af83 no ln_VNetINT
veth100i0 --> Link to LXC (Interface 0)
fwbr100i1 8000.92db95dc2dd1 no fwln100o1
veth100i1 --> Link to LXC (Interface 1)

---

ovs-vsctl list-ports vmbr0
enp0s3
fwln100o1 ---> new interface added (supposed as intf. for adding a firewall rules)?
ln_VNetINT

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Case when starting LXC conatiner with only one interface (LXC No. 102);

brctl show
bridge name bridge id STP enabled interfaces
VNetINT 8000.2ef33389af83 no ln_VNetINT
veth102i0 ---> --> Link to LXC (Interface 0)
ovs-vsctl list-ports vmbr0
enp0s3
ln_VNetINT

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So in this case:
[OVS] [Linux]

(NIC) enp0s3 <--> (Bridge) vmbr0 <---------> ln_VNetINT <==============> (Bridge) VNetINT <--> ln_VNetINT
<--> veth102i0

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ip -d link ----> command output summary

2: enp0s3: master ovs-system ...
openvswitch_slave
4: vmbr0: ...
openvswitch
6: ln_VNetINT: master VNetINT ...
openvswitch bridge_slave
7: VNetINT: ...
bridge
alias Internal network segment
12: veth102i0@if2 master VNetINT ...
bridge_slave

---

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General questions i have here is the purpose of the interfaces:

• ln_VNetINT
• VNetINT
• fwlnXXXoYY

I am asking for this because i want to create a Linux network stack + OpenStack + Proxmox VE network, as it is on my initial drawing:
Linux network stack


Br,
Hrvoje.