ovs-vxlan&vlan

In the Open vSwitch environment, a packet is sent from the instance to a physical NIC generally will go through the following several types of devices:

1. tap interface named tapXXXX.

2. linux bridge named qbrXXXX.

3. veth pair named qvbXXXX, qvoXXXX.

4. OVS integration bridge named br-int.

5. OVS patch ports designated int-br-ethX and phy-br-ethX (X is the number interface).

6. OVS Provider Bridge named br-ethX (X is the number interface).

7. Physical interface named ethX (X is the number interface).

8. OVS tunnel bridge named br-tun.

OVS provider bridge will be used in flat and vlan network; OVS tunnel bridge and will be used in vxlan gre network.

 

 

 

 

 

1.1 VXLAN implementation model

 

The conversion process messages

1. Virtual Machine (VM) issued Untag message
2. After qbr-xxx, the message is still Untag
3. Entering br-int, a tag marked VLANID = N
4. Leaving br-int, VLANID = N
5. Entering br-tun, VLANID = N
6. Leaving, VLAN encapsulation of VXLAN, and VNI = M

Note: When the br-tun, VLAN becomes VXLAN, and converted VNI = 100.

The conversion process messages

1. Before the message from the host to br-tun, it is VXLAN packets, VNI = M;
2. Entering the br-tun, it is converted to a VLAN packet, VLANID = N;
3. After leaving to enter from the br-tun br-int, are tag packets, VLANID = N;
4. When the br-int, becomes Untag;
5. Into a virtual machine (VM) by qbr-xxx

1.2 vlan implementation model
and model VXLAN achieve substantially the same, except that the br-tun becomes br-ethx.
 

 

 

 

The conversion process messages

1. After the virtual machine (VM) issued as Untag message
2. After qbr-xxx, or Untag message
3. Upon entering br-int, it is labeled before, VLANID = N, and when leaving br-int still VLANID = N
4. Upon entering br-ethx, marked with a tag VLANID = M
5. When leaving br-ethx, i.e. away from the host Host, VLANID = M.

I.e., when the tag the tag becomes br-int, an ID tag the packet in the conversion br-ethx.

The conversion process messages

1. Enters from the Host br-ethx, to tag packets, VLANID = M;
2. Leaving br-ethx, VLANID = N;
3. Entering br-int, VLANID = N;
4. When the br-int, becomes Untag;
5. By qbr-xxx into the virtual machine (VM)