CentOS 7 + VXLAN

Community Support
1

Hello,
Anyone have experiance with ONe + CentOS + VXLAN?
I use Openvswitch but have task migrate to VXLAN. I try add VXLAN network but every time have error - Can’t add port to bridge .
Maybe anyone can write small how-to?
Thanks!

2

would you paste here log from VM creation - part where network was creatin

3

Now VM can start without errors (I forget add PHYDEV) but network not working. I can’t find any docs about VXLAN in Centos 7 and kvm. On test servers I can create vxlan network only between physical servers.

4

I thing what I imagine is that on centos 7 you hve to disable firewalld, because opennebula uses iptables and adds own forward rules and also enables bridge net filter. also you have to enable ipv4 forward in sysctl

5

I’m using a modifed OVS driver supporting VXLAN for communication between hypervisors. Works fine. It’s a kind of merge between OVS and VXLAN drivers. So each VNI becomes a VLAN domain. But since it’s build over the OVS driver you won’t have security groups (dunno if you have them with the VXLAN driver tho)

6

Hello,
You can provide yours ifconfig, brctl show and ovs-vsctl show?
Thanks!

7

Hi Anton,

Here is what is important:

Each VNI (VXLAN) as it’s own ovs Bridge (brvx$VNI), with an interface vx$VNI as internal port used for connecting other members of this VXLAN on other hypervisors

Bridge "brvx20208"
        Port "one-4024-5"
            tag: 208
            Interface "one-4024-5"
        Port "one-4024-1"
            tag: 208
            Interface "one-4024-1"
        Port "one-4024-4"
            tag: 208
            Interface "one-4024-4"
        Port "brvx20208"
            Interface "brvx20208"
                type: internal
        Port "vx20208"
            Interface "vx20208"
        Port "one-4024-3"
            tag: 208
            Interface "one-4024-3"
        Port "one-4024-2"
            tag: 208
            Interface "one-4024-2"

[root] # ip -d l show dev vx20208
447: vx20208: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 8950 qdisc noqueue master ovs-system state UNKNOWN mode DEFAULT qlen 1000
    link/ether 0e:c5:c1:f0:e7:7c brd ff:ff:ff:ff:ff:ff promiscuity 1 
    vxlan id 20208 group 239.0.78.240 dev vlan4060 srcport 0 0 dstport 8472 ttl 16 ageing 300 
    openvswitch_slave addrgenmode eui64

Each VX interface use a MC group. This MC group IP is calculated from portion of code from the ONE VXLAN driver.

Sorry I don’t have ifconfig nor brctl commands.

So if you use a ONE VNET with same VNI and VLAN, VM can communicate.
Hope it helps.

8

Hello Edouard,
What is vx20208 interface?

9

vx20208 is the VXLAN interface that is given to the OVS bridge, allowing ethernet frames to be encapsulated inside the VXLAN. It’s like an uplink on a switch, but this one will use VXLAN to communicate to other switches (like other OVS bridges on other hypervisors).

10

Thanks, but it did not help me. Probably I have little experience to use vxlan. :slight_smile:

11

Hello,
Now I have working VXLAN network but only on one node if I migrate VM to another node - no network.
What’s wrong?
Thanks!

12

Resolve problem. (wrong network settings). Now all works excellent.
Thanks to all!
Happy Christmas and New Year!