The MPLS WG Archive

[Ajay Simha <asimha@cisco.com>]

On Thu, 26 Apr 2001, Hari Kishan wrote:

>
> To be more specific,
> can it be only the list of all MPLS enabled/capable interface
> addresses on that LSR? or can it have something more ?

I think it should be the list of all MPLS enabled/capable interfaces and
nothing more.  These interfaces as I mentioned in my last email get used
when the route to a prefix changes.  Look at example:

 10.0.1
+-------+
A       B
+-------+
 10.0.2

A=.1
B=.2

RIB On A:
Dest prefix: 200.1.1.1
Next hop   : 10.0.1.2

LIB on A:
Remote lbl : 25, LSR-ID=B
Addresses bound to B: 10.0.1.2, 10.0.2.2

LFIB on A:
Dest prefix :200.1.1.1
Out label   :25
Out Intf    :Pos 2/1

Then 10.0.1 link goes down and the routing entry now looks like:
Dest prefix: 200.1.1.1
Next hop   : 10.0.2.2

Now since the session is up (due to 10.0.2 link), A tries to use same
label binding it received from B.  Since it is going to send a labeled
packet, 10.0.2.2 interface on B better be MPLS enabled.

Assumption here is that B is doing per-platform label space.

-ajay

 >
> --kishan
>
> -----Original Message-----
> From: Ajay Simha [mailto:asimha@cisco.com]
> Sent: Thursday, April 26, 2001 11:25 AM
> To: Hari Kishan
> Cc: mpls@UU.NET
> Subject: Re: Address message ?
>
>
> On Thu, 26 Apr 2001, Hari Kishan wrote:
>
> > Hi,
> >
> >   What exactly are the addresses a LDP peer
> >   advertises in it's Address message before
> >   sending label advertisements?
> >
> >   Is it a list of addresses configured on a
> >   particular interface or can it be any arbitrary
> >   list of addresses the peer is configured to
> >   advertise.
>
> I would think it should be the addresses that are configured on
> interfaces
> not arbitrary list of addresses.  Because these addresses could be
> used
> later to dip into the LIB if for example one of the links to that
> neighbor
> goes away and we continue to have a session.  We still want to use the
> label bindings this neighbor sent us earlier.
>
> -ajay
>
>  >
> > thanks,
> > Kishan
> >
> > ---------------------------------
> > Hari Kishan Desineni,
> > Ericsson Inc,
> > Data Backbone & Optical Division,
> > Santabarbara,
> > California - 93117
> > Office:(805) 562 6419
> > Home:(805) 968 1894
> >
>
> --
> Ajay Simha
> MPLS Deployment Engineer
> IOS Technology Division
> (919) 392-3141
>
> "Study as if you were to live forever
>  Live as if you were to die tomorrow"
>
>  - Mahatma Gandhi
>
>

-- 
Ajay Simha
MPLS Deployment Engineer
IOS Technology Division
(919) 392-3141

"Study as if you were to live forever
 Live as if you were to die tomorrow"

 - Mahatma Gandhi