[c-nsp] Sub-int based EoMPLS on a 6700 series LC in a 7600

[Gert Doering]

Hi,

On Tue, Mar 17, 2009 at 08:53:14AM -0500, Justin Shore wrote:
> So if I'm touching the CEs with trunks on both ends and a tagged VLAN on 
> each end is being used, is the Q tag being stripped as it goes across or 
> is it being carried?  

As far as I understand, it's stripped.  (You can have "vlan 52" on the
left and "vlan 300" on the right side... PVSTP will be unhappy, but that's
an independent issue).

> Even if it's being carried and the MTU is too low 
> to carry the tag on large frames I should still get small frames through 
> shouldn't I?  

Yes.  ("Been there, done that, when I did port-mode and tried to get
dot1q tagged packets across").

> I could always switch the trunks around to put the 
> xconnect on the native VLAN on each side.  That's easily done if that 
> would help.

I don't think it would help - more likely, use of native VLAN will
confuse things even *more*

> >Not on the 7613.  Dunno about the ME boxes.
> 
> On the ME3750 I'm using the dedicated GigE uplinks for the core-facing 
> ints.  I believe those 2 ports are the only ones that you can enable 
> MPLS on for that odd platform.  So that should be ok.
> 
> >(We do EoMPLS over 6408A-GBIC, 6724-SFP and 6704-10GE cards, never had any 
> >problem with it)
> 
> That's good to hear.  So to be clear you're using 6700 series cards both 
> for the core-facing interfaces and for the CE-facing interfaces (using 
> sub-ints or full ports), correct?

Yes.  Some of the 6700 cards have DFCs, some have CFCs.

We've pretty much everything everywhere.

Non-MPLS side: Sup32 onboard GE
               Sup720-10G onboard GE
               6724-SFP/CFC
               6408A-GBIC (dumb bus card, no CFC/DFC)
MPLS side: vlan on portchannel on Sup32 onboard GE ports
           vlan on switched 6708-10GE/DFC port
           vlan on switched 6704-10GE/CFC port
           routed on 6408A-GBIC port
           
and this all "just works".  No SR* IOS, though - SXF, SXH3a, SXI.

No ME boxes, though (as mentioned).

> I was pretty sure that this should work.  My TAC engineer got back to me 
> last night and is saying that won't work which I don't think is correct. 
>  Specifically they said:
> 
> "On the 7600, a PFC/DFC or ingress line card (SIP-400/ES20) that does 
> EoMPLS Label imposition/deposition is needed as a MPLS uplink port."

Well.  Technically he is right: you need a PFC/DFC.  That means, if you
have a 7600 with a Sup1 or Sup2, it will *not* do MPLS without an OSM card.

If you have a Sup720-3B/Sup32 or higher, you have a PFC... and MPLS on
LAN cards is explicitely supported there.

*V*PLS won't work without a SIP/ES20 card.

> Well my 6700 LCs all have DFCs; I wouldn't buy them any other way.  The 
> engineer goes on to imply that the VC type on either end is the problem. 
>  Well the VC type is the same on both ends and is working because the 
> VC is up; a mismatch would keep it down (been there done that).  The 
> engineer then gave a description of port-to-port, vlan-to-vlan and 
> port-to-vlan modes, their VCs and how the operate on the 7600.  This 
> should be a VC type 5 port-to-vlan VC I believe (sub-int to SVI). 
> That's what both sides agree on when the VC comes up.

That "SVI" part might be the problem.

I know that the 7600 can *not* do SVI-based EoMPLS - you need to have
a subinterface (VLAN-to-*) or dedicated port (Port-to-*).

I don't know the capabilities of the ME.

(What I'd do next is to try to sniff packets going back and forth over the 
core links, with the appropriate MPLS labels.  Just to see who is sending
and/or receiving what)

gert
-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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