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On 31 Oct 2014, at 14:55, Haris Rotsos <cr409@xxxxxxxxxxxx> wrote:

On 30 October 2014 13:42, Richard Mortier <Richard.Mortier@xxxxxxxxxxxxxxxx> wrote:
all;

to take a slightly different tack on this -- is there anyone out there successfully running mirage unikernels on xen that make use of >1 network interface? how did you configure this?

I think Masoud found that the problem was in Netif naming. In the earlier version of the mirage-net library, the Manager would provide direct access to the device names and there was higher programmability in netif programmability. I think Masoud got this right.

haris-- what did you do for the mirage openflow paper?

As I mentioned to Masoud, I basically used oflops together with the pktgen kernel module for high throughput traffic generation.

Two critical points to get things working is to make separate bridges for each vif pair in the Dom0 and also, if you are planning to work with iperf and real applications, you must disable tx offloading on the non-unikernel VMs. I remember I had a problem to get TCP connections across a mirage switch because I was getting bad checksums on the receiver side.

more generally-- is http://wiki.xenproject.org/wiki/Xen_Networking the canonical location for info on how to configure and manage networking on xen vms?

and presumably all this results in entries in xenstore-- are http://wiki.xen.org/wiki/XenStore andhttp://wiki.xen.org/wiki/XenStore_Reference the canonical documentation for xenstore and it's use by network devices?

is there any documentation available on how to debug openvswitch networking on xen via xenstore (or through some other means)?

I think ovs doesn't do anything special for Xen vifs in comparison to traditional ethernet linux devices. The only debugging I usually do is to check through the `ovs-vsctl show` if vif are assigned to the appropriate bridges.

On 26 Oct 2014, at 20:06, Masoud Koleini <Masoud.Koleini@xxxxxxxxxxxxxxxx> wrote:

>
> I have defined 3 vifs with 3 different mac addresses for the 3 tap
> devices that I am using, and switch shows the same mac address (mac
> address of the first defined vif) assigned to both tap2 and tap3.
>
> Another issue that I faced is, although I can ping switch vm, nothing
> appears on vifs and xenbr0 when switch starts a TCP connection to a
> remote controller (using TCPV4 create_connection function). This
> function works well for unix config.
>
> On 26/10/14 11:43, Anil Madhavapeddy wrote:
>> On 25 Oct 2014, at 11:36, Masoud Koleini <masoud.koleini@xxxxxxxxxxxxxxxx> wrote:
>>> Hi all,
>>>
>>> I have a switch with three tap devices tap0 (for the controller connection), tap1, and tap 2 running on Xen.
>>>
>>> What would be the right VIF configuration for Xen?
>> It would be pretty much the same configuration as your tap setup. The Xen networking model is to expose a VIF ('virtual interface') in the guest and dom0. Everything else from there is host setup and can be customised -- most commonly by adding a bridge to the outside world and adding the VIFs from the guests to that bridge so they can communication externally.
>>
>> The xl setup fragment looks like:
>>
>> vif = [ 'bridge=xenbr0' ]
>> or
>> vif = [ 'mac=c0:ff:ee:c0:ff:ee,bridge=br0' ]
>>
>> -anil
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--
Cheers,

R.

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--
Charalampos Rotsos
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The University of Cambridge
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--
Cheers,

R.

Re: [MirageOS-devel] Xen VIF configuration for tap devices