2009/317 Solaris PPP/PPPoE Updates

[James Carlson]

Darren Reed writes:
> James Carlson wrote:
> > where session-SAP and discovery-SAP are used to set the SAP values for
> > sppptun.  The problem described in the original bug report could now
> > be handled by using:
> >
> > 	e1000g0 3c13 3c12
> 
> What use do you forsee for these new configuration options?
> ... why would I ever want to change it?

As cited in the original materials, CR 4695172 documents an
interoperability issue with 3COM servers.

Those servers (for reasons that are substantially unclear, but
probably relate to changes in the documentation before publication)
use a different set of Ethertypes.

> To me, it looks like I never would, so I'm wondering if these
> new interfaces are even necessary?

Roaring Penguin (the Linux PPPoE) includes a very similar feature for
exactly the same reason.  You use "-f disc:sess" to set the Ethertypes
when you launch the daemon.

In fact, I believe they added this for exactly the same reason: to
interoperate with those 3COM servers.

> A non architectural question...
> What happens if they're configured in reverse or to be the same#?

If they're reversed, then the user likely won't be able to connect.
We'll send out the discovery packets using the session Ethertype and
vice-versa.  If they're the same, then we'll send all of the packets
with the same Ethertype.  (If the peer happens to be a Solaris server,
both of these cases would actually work, because our kernel design
happens to use a single function for dispatching the inbound packets,
and we just don't care which Ethertype is used.)

Knowing the right numbers to set is important if you want to use this
feature at all.

Don't forget that these are optional.  The following entry in
/etc/ppp/pppoe.if will still work and will still give you the RFC 2516
default:

	e1000g0

-- 
James Carlson, Solaris Networking              <james.d.carlson at sun.com>
Sun Microsystems / 35 Network Drive        71.232W   Vox +1 781 442 2084
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