Re: [neutron][ovn] both vxlan and geneve cannot get full bandwidth

28 Apr 2025


      Hello.
My physical network has 9000 MTU and when doing tests I use 1500 MTU for
both vlan and geneve.
Nguyen Huu Khoi


On Tue, Apr 29, 2025 at 4:05 AM Jeremy Stanley <fungi@yuggoth.org> wrote:
...
On 2025-04-28 23:22:29 +0700 (+0700), Nguyễn Hữu Khôi wrote:
[...]
...
It happened only with geneve and vxlan. I can get full bandwidth
with vlan.
[...]
If you're seeing significant bandwidth reduction with encapsulated
virtual networks, you may be fragmenting and doubling the number of
frames needed. Make sure the MTU of the physical network is
sufficiently larger than the encapsulated MTU to account for the
encapsulation overhead.
--
Jeremy Stanley