On 01/02/2015 08:12 PM, Johnny Billquist wrote:
One can tunnel most anything over GRE, even raw Ethernet frames,
regardless of the higher-level protocols. Hence the 'G' for
"Generic".
Yes. But you need some ingress and egress that makes use of it. Or else
we could just as well argue that UDP can tunnel anything.
...which it can. ;) On a Cisco, assigning a DECnet cost to an
interface (and a GRE endpoint is a pseudo-interface on a Cisco) forms
that ingress/egress.
(I know YOU know this; I'm saying it for the benefit of those here who
are just learning about this)
Actually, I don't know the details, even though I pretty much know how
it *could* be done. I've pretty much never actually worked on a Cisco
box. :-)
However, DECnet costs cannot possibly be related, as we're now not
talking about DECnet protocols. (LAT and MOP are not using DECnet...)
You need to somehow tell the Cisco box to grab all ethernet packets with
a certain protocol number, and pass those on over the tunnel, and have
the other end do the reverse.
Assigning a DECnet cost to a tunnel endpoint pseudo-interface causes
it to pay attention to DECnet packets.
-Dave
--
Dave McGuire, AK4HZ/3
New Kensington, PA