Merge pull request #646 from alauda/docs/vlan

docs: add underlay docs

README.md

@@ -34,7 +34,7 @@ The Kube-OVN community is waiting for you participation!
 - **BGP Support**: Pod/Subnet IP can be exposed to external by BGP router protocol.
 - **Traffic Mirror**: Duplicated container network traffic for monitoring, diagnosing and replay.
 - **Hardware Offload**: Boost network performance and save CPU resource by offloading OVS flow table to hardware.
-- **Vlan Support**: Kube-OVN also support underlay Vlan mode network for better performance and throughput.
+- **Vlan/Underlay Support**: Kube-OVN also support underlay and Vlan mode network for better performance and direct connectivity with physic network.
 - **DPDK Support**: DPDK application now can run in Pod with OVS-DPDK.
 - **ARM Support**: Kube-OVN can run on x86_64 and arm64 platforms.
 - **VPC Support**: Multi-tenant network with overlapped address spaces.
@@ -75,7 +75,7 @@ If you want to install Kubernetes from scratch, you can try [kubespray](https://
 - [BGP support](docs/bgp.md)
 - [Multi NIC Support](docs/multi-nic.md)
 - [Hardware Offload](docs/hw-offload.md)
-- [Vlan Support](docs/vlan.md)
+- [Vlan/Underlay Support](docs/vlan.md)
 - [DPDK Support](docs/dpdk.md)
 - [Traffic Mirror](docs/mirror.md)
 - [Webhook](docs/webhook.md)

docs/vlan.md

@@ -1,15 +1,18 @@
-## Vlan Support
+## Vlan/Underlay Support
 
 By default, Kube-OVN use Geneve to encapsulate packets between hosts, which will build an overlay network above your infrastructure.
 Kube-OVN also support underlay Vlan mode network for better performance and throughput.
 In Vlan mode, the packets will send directly to physical switches with vlan tags.
 
 To enable Vlan mode, a dedicated network interface is required by container network.
-The related switch port must work in trunk mode to accept 802.1q packets.
+The related switch port must work in trunk mode to accept 802.1q packets. For underlay network with no vlan tag, you need
+to set the VLAN ID to 0.
 
 By now, Geneve or Vlan network mode is a global install option, all container must work in the same network mode.
 We are working at combine two networks in one cluster.
 
+![topology](vlan-topolgy.png "vlan network topology")
+
 ### Install Vlan mode
 
 1. Get the installation script