[ovs-dev] OVN: Preserving state between logical datapaths

[Ben Pfaff]

On Thu, Feb 16, 2017 at 08:46:34PM +0500, Valentine Sinitsyn wrote:
> Imagine you want to mark a packet in logical switch datapath then use this
> mark in logical router datapath somehow (an artificial use-case would be
> policy routing based on VM port, not destination IP address).
> 
> Is there a better way than using packet mark (which also doesn't seem to
> survive "output" action, yet it's easily fixable)? I assume OVS/OVN 2.6 on
> Linux with in-kernel datapath, if this matters.

The main issue for preserving metadata from one logical datapath to
another is that there needs to be a way to do it when we cross from one
hypervisor to another.  This is straightforward in Geneve, by adding an
extra option.  So far, we haven't had enough motivation to add extra
options for this purpose.