[ovs-discuss] ovs between namespaces

Justin Pettit jpettit at nicira.com
Tue Jul 2 16:19:50 UTC 2013


Please don't drop the list.

veths are a standard way to get traffic between namespaces.  The overhead of veths should be minimal; there's not a lot to them.

--Justin


On Jul 2, 2013, at 9:14 AM, Daniele Venzano <venza at brownhat.org> wrote:

> Ok, I can do that, but why the veth is needed?
> Doesn't it affect performance to have packets being sent through the virtual link?
> 
> Thanks,
> Daniele
> 
> Il 02/07/2013 18:07, Justin Pettit ha scritto:
>> A veth will have two ends. Attach one to OVS and put the other in a namespace.  If you have three namespaces, create three veths. 
>> 
>> --Justin
>> 
>> 
>> On Jul 2, 2013, at 8:12 AM, Daniele Venzano <venza at brownhat.org> wrote:
>> 
>>> Ok, let's say I have three namespaces. I want to use ovs. How can I do that?
>>> 
>>> Thanks,
>>> Daniele
>>> 
>>> Il 02/07/2013 15:41, Tomasz Paszkowski ha scritto:
>>>> Hi,
>>>> 
>>>> use veth interface for that purpose.
>>>> 
>>>> 
>>>> On Tue, Jul 2, 2013 at 3:34 PM, Daniele Venzano <venza at brownhat.org> wrote:
>>>> Hello,
>>>> 
>>>> I'm trying to connect two network namespaces (ip netns) with a two port openvswitch, on the same physical machine. I've had no success.
>>>> 
>>>> Up to now I tried with this command sequence:
>>>> 
>>>> ===
>>>> ip netns add test_ns1
>>>> ip netns add test_ns2
>>>> 
>>>> ip tuntap add dev tap1 mode tap
>>>> ip tuntap add dev tap2 mode tap
>>>> 
>>>> ovs-vsctl add-br test_br
>>>> ovs-vsctl add-port test_br tap1
>>>> ovs-vsctl add-port test_br tap2
>>>> 
>>>> ip link set tap1 netns test_ns1
>>>> ip link set tap2 netns test_ns2
>>>> 
>>>> $EXEC_NS1 ifconfig tap1 192.168.1.101 up
>>>> $EXEC_NS2 ifconfig tap2 192.168.1.102 up
>>>> 
>>>> $EXEC_NS1 ping -c 2 192.168.1.102
>>>> ===
>>>> 
>>>> The ping at the end reports "Destination Host Unreachable".
>>>> 
>>>> I tried also with the following variations, with no success either:
>>>> 
>>>> 1. wrote a program that creates the tap interfaces and keeps them open instead of using "ip tuntap". No data is read on either tap1 or tap2 on the file descriptor.
>>>> 
>>>> 2. create tap1,2 inside the namespaces and connect them from there instead of creating in the default ns and then moving them.
>>>> 
>>>> The ovs log is full of errors since, after moving the interfaces inside the namespace, it is unable to find them. Apparently this is normal and accepted behaviour, according to google.
>>>> 
>>>> What am I doing wrong?
>>>> How can I query some status out of ovs? Stuff like port status, counters, etc?
>>>> 
>>>> Thanks,
>>>> Daniele
>>>> 
>>>> -- 
>>>> Daniele Venzano
>>>> http://www.brownhat.org
>>>> 
>>>> _______________________________________________
>>>> discuss mailing list
>>>> discuss at openvswitch.org
>>>> http://openvswitch.org/mailman/listinfo/discuss
>>>> 
>>>> 
>>>> 
>>>> -- 
>>>> Tomasz Paszkowski
>>>> SS7, Asterisk, SAN, Datacenter, Cloud Computing
>>>> +48500166299
>>> 
>>> 
>>> -- 
>>> Daniele Venzano
>>> 
>>> http://www.brownhat.org
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> discuss mailing list
>>> discuss at openvswitch.org
>>> http://openvswitch.org/mailman/listinfo/discuss
> 
> 
> -- 
> Daniele Venzano
> 
> http://www.brownhat.org
> 
> 
> 




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