[ovs-discuss] How does MTU work with tunnels?

Benjamin benjamin.reis at vates.fr
Tue Sep 10 13:48:36 UTC 2019


Thanks for your quick answer.

But i'm not sure I understand what you're saying: max MTU for VxLAN 
would be 1320?

Le 10/09/2019 à 15:26, Heim, Dennis a écrit :
> I run VXLAN over a DMVPN setup, as it is part of our Lab/PoC architecture (distributed). From an MTU perspective, Windows is happy with 1360, but some linux/apache servers require it set to 1320 to work properly.
>
> Dennis Heim | Domain Architect (Collaboration Labs)
> World Wide Technology, Inc. | +1 314-212-1814
>
>
>
> "The most powerful person in the world is the story teller. The storyteller sets the vision, values and agenda of an entire generation that is to come" - Steve Jobs
> "Leadership isn't a different maker. It is the difference maker" - Tim Kight
> "Leaders who don't listen will eventually be surrounded by people who have nothing to say" --- Andy Stanley
> "Worry less about who you might offend, and more about who you might inspire" -- Tim Allen
> "Imagination is more important than knowledge."  -- Albert Einstein
> "If you can raise the level of effort and performance in those around you, you are officially a leader" - Urban Meyer
> "The greatest danger for most of us is not that our aim is too high and we miss it, but that it is too low and we reach it." -- Michelangelo Buonarroti
> "Mediocore managers play checkers (assuming everyone is the same). Great managers play chess (acknowledging that everyone is unique)" - Marcus Buckingham
> "If you're not failing every now and again, it's a sign you're not doing anything very innovative" - Woody Allen
>
> Click here to join me in my Collaboration Meeting Room
>
> -----Original Message-----
> From: ovs-discuss-bounces at openvswitch.org <ovs-discuss-bounces at openvswitch.org> On Behalf Of Benjamin
> Sent: Tuesday, September 10, 2019 9:04 AM
> To: ovs-discuss at openvswitch.org
> Subject: [ovs-discuss] How does MTU work with tunnels?
>
> Hi all,
>
> I working with openvswitch 2.5.3 (tried with 2.11.0 same behavior) on XCP-ng (XenServer fork).
>
> I'm trying to undersand how the mtu works with GRE and VxLAN tunnels.
> As for now when I create a GRE tunnel with any MTU, I think the MTU is not taken in consideration because i can ping -s 15000 on the corresponding interface.
> However, with VxLAN if I set a MTU greater than 1450 then the MTU is
> 1450 and if I set a MTU lower than 1450 I have same behavior as for GRE.
>
> So I'm a but confused.
>
> When I check the mtu value with : ovs-vsctl get int xapi0 mtu_request or ovs-vsctl get int xapi0 mtu the returned value is what I expect.
>
>
> Thanks in advance,
>
> Benjamin
> _______________________________________________
> discuss mailing list
> discuss at openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-discuss



More information about the discuss mailing list