Eric, that's not what Lane is asking. He wants to know if
an option exists on the Junipers to do ultimate hop popping.
The feature you described was put in because the default
IOS behavior is to signal label value 0 as "implicit null",
which does not correspond to spec.
Lane, on both Juniper and Cisco, you can't change the
penultimate hop popping behavior. Juniper would only signal
explicit-null for single hop tunnels for purposes of
preserving the exp field, but I am not sure if this is
still the case. I can send details privately. At one point,
I had to have Juniper folks build a custom image that did
not do this. The topology was such where single hop LSPs
were configured between a directly adjacent 12008 and M40.
The GSR would signal the incorrect implicit-null value (0)
to the M40. So when the LSP was setup, the Juniper was
expecting encapsulated traffic and the Cisco was actually
doing penultimate hop popping. This caused all frames to
be ignored on the Juniper side. That was half the problem.
The LSP that originated from the Juniper during setup
requested explicit-null; I have to reference notes, but I
seem to remember either the LSP signalling would fail or
the LSP would be established, or the traffic was dropped due
to misinterpretation of the implicit/explicit null behaviors.
Can I ask why you want to do ultimate hop popping?
- Serge
Thus spake Eric Osborne (eosborne@cisco.com):
> On Mon, Apr 02, 2001 at 10:49:29PM +0200, Jesper Skriver wrote:
> > On Mon, Apr 02, 2001 at 01:43:22PM -0700, Lane Patterson wrote:
> > >
> > > It appears that if I want to use a Juniper as an egress LSR, I MUST
> > > use penultimate hop popping? For example, using signalled LSPs,
> > > juniper will only send RESV's with a "3" label (implicit NULL), and
> > > I don't see knobs for it to use an IPv4 explicit NULL "0" label.
> >
> > Just like Cisco ...
> >
>
>
> gsr1(config)#mpls traffic-eng signalling advertise ?
> implicit-null Use MPLS encoding for Implicit-Null Label in signalling
> messages
>
>
>
>
>
> eric
>
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