[ovs-discuss] Tunneling Setup Questions

[Tony Finn]

I have found the issue, so you can ignore this post, just adding it here 
in case anyone else runs into this problem:

All involved interfaces on the OVS VMs need to have promiscous mode 
enabled in the Virtualbox config or Virtualbox will silently drop the 
forwarded packets.

Regards,
Tony

On 12/04/2015 15:04, Tony Finn wrote:
> Hi all,
>
> I'm currently trying to set up a test setup for tunnelling using Open
> vSwitch. As this was originally to to investigate Geneve, I have built
> the latest release from the master branch, but the issues I have also
> occur when I try to use GRE so I suspect the problem is user error
> rather than anything to do with incomplete Geneve support.
>
> The setup I'm trying to create is as follows:
>
>
> client1(10.0.0.1) ---|        (br-ext 10.0.10.1)        (br-ext
> 10.0.10.2)     |---- client 3 (10.0.0.3)
>                                   |--------- [OVS1] - - - - Tunnel - -
> - - [OVS2]  --------|
> client2 (10.0.0.2)---|        (br-int 10.0.0.5) (br-int 10.0.0.6) |----
> client 4 (10.0.0.4)
>
> All the clients and OVS devices are virtualbox VMs.
>
> What I have done so far:
>
> Setup two bridges on each OVS1 and OVS2. The first, br-ext has one port,
> the external connection between OVS1 and OVS2. On OVS1 I have given it
> the IP address 10.0.10.1 and on OVS2 I have given it the IP address
> 10.0.10.2. The second is br-int. On each OVS VM it is connected to three
> ports - the two external connections to the client machines connected to
> that OVS, and a tunnel port. The VMs themselves are given IP addresses
> ranging from 10.0.0.1/24 to 10.0.0.4/24 .
>
> I have tried using both Geneve and NVGRE for the tunnel port, using GRE
> I used the command (on OVS1):
>
> ovs-vsctl add-port br-int gre1 -- set interface gre1 type=gre
> options:remote_ip=10.0.10.2
>
> and on OVS2:
>
> ovs-vsctl add-port br-int gre1 -- set interface gre1 type=gre
> options:remote_ip=10.0.10.1
>
> When trying Geneve I had used the same command except with type=geneve
> and a port name of geneve1.
>
> However, using both Geneve and NVGRE I had the same outcome:
>
> client1 and client2 are able to ping OVS1's br-int
> client3 and client4 are able to ping OVS2's br-int
> OVS1 is able to ping OVS2's br-ext
>
> However, clients, even those on the same OVS bridge are not able to ping
> each other. Using Wireshark, I can see the ARP requests being sent from
> the client, including GRE encapsulated packets being sent across the
> tunnel. However, the clients do not appear to be receiving these packets
> as they never send an ARP reply of their own.
>
> Is there anything I have missed?
>
> Other potentially useful information:
>
> * This is all running on Arch Linux, using kernel 3.19 with the kernel
> provided openvswitch module
> * None of the physical interfaces involved are assigned IP addresses,
> only the bridges
> * The clients and OVS machines were cloned from each other, but MAC
> addresses have been randomised.
> * The OVS machines have one other interface, assigned an IP address
> 10.0.2.15/24 for external internet address. This is also the default
> gateway on these machines.
>
> Regards,
> Tony Finn
>
>
>