[ovs-discuss] GRE key rules

[Paul Greenberg]

Bilal,

Regarding n^2 interfaces, I think you can have a single GRE interface without remote_ip set. Instead, the interface is "flow" type interface. Otherwise, the diameter of your network is very limited, because of limited number of interfaces you can create.

It is similar to how Geneve interface works in OVN. There, you have a single point-to-multipoint Geneve tunnel interface. Additionally, there are rules to set outer header destination IP address.

Regards,
Paul

Best Regards,
Paul Greenberg
________________________________
From: William Tu <u9012063 at gmail.com>
Sent: Wednesday, May 30, 2018 1:16:15 PM
To: Bilal Saleem
Cc: Paul Greenberg; ovs-discuss at openvswitch.org
Subject: Re: [ovs-discuss] GRE key rules

On Tue, May 29, 2018 at 2:47 AM, Bilal Saleem <mbs10 at nyu.edu> wrote:
> Thanks, Paul and William.
>
> But in my topology, there could be multiple hosts and for that, I might need
> to create n^2 tunnels (from each host to other hosts), and even if I go with
> that I think I need to know the remote IP addresses  (correct me If I am
> wrong) and that I don't know as I don't know how many hosts could be in
> topology.
>
> I am using C code to create a GRE packet rather than to let switch add gre
> headers fields, it is a requirement of the algorithm.
>
> I have used tunnel_id and tunnel_id_nxm field but does not work. all packets
> match the rules where the tunnel_id value is 0. I think that is because I am
> not creating a gre interface.
>
> Other questions:
> Do I have to create gre interface on each switch?
>
Yes, to use gre tunnel in OVS, you have to create gre interface.

> Is it possible to do this without creating gre tunnel interface at switch?
>
No.

William
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openvswitch.org/pipermail/ovs-discuss/attachments/20180530/9ab6ab86/attachment.html>