[ovs-discuss] gre and mtu

[Jesse Gross]

On Wed, Nov 13, 2013 at 5:33 AM, Vasiliy Tolstov <v.tolstov at selfip.ru> wrote:
> Hi all.
> If i have vm with mtu setting inside it to 1500, does that mean i need
> to raise mtu on host side if i use gre tunnels to conect nodes?
> If need - on which interface i need to do that in case:

You should raise the MTU along all interfaces after GRE encapsulation,
which in this case would be the physical interface.

> Oh and second - does i need to specify key in gre tunnels? Or i can ommit it?

You can leave out the key if you don't need it.