The MPLS WG Archive

["Thomas D. Nadeau" <tnadeau@cisco.com>]

>Thanks for your reply. But I am still missing something -
>the tunnel creation part is fine, but when I need to
>access information about L2 (the LSP tunnel), I have a problem.
>What I would need is: given LSP L1 (i.e., knowing its
>mplsTunnelIndex), I need to find out which tunnel it is
>going through, how much bandwidth is left on this tunnel L2,
>what is the ingress/egress LSR id, etc.  For those info
>I would probably need the mplsTunnelIndex for L2.

         What you are asking is for a reverse mapping from
XCEntry->TunnelEntry. This is not available directly. What you
would have to do is traverse your tunnel heads (we recommend
that the tunnelInstance = 0 for these for ease of look up). Then
for this set check the tunnelXCpointer.

>If I am not misunderstanding the MIBs, this mplsTunnelIndex
>(of L2) does not appear in either interface table or
>out segment table. - any comments?

         The tunnel's ifIndex (if implemented as an interface) is
specified in the tunnelEntry. The tunnel's ifIndex can (and must) appear
in the ifEntry if the tunnel is implemented as a ifIndex.  TunnelEntries
were not indexed by ifIndex because some implementations did not want
to implement them that way, which would have made the indexing
useless for them.

         --Tom



>Thanks,
>Fang
>
>-----Original Message-----
>From: Adrian Farrel [mailto:afarrel@movaz.com]
>Sent: Friday, July 19, 2002 2:22 PM
>To: Fang Hao
>Subject: Re: Question on MIB info for LSP tunneling
>
>
>Fang,
>
>A common approach top this is to install the tunnel as an interface so it
>shows
>in the interfaces MIB.  The interface would also show in the TE MIB for the
>tunnel.
>
>The tunneled LSP can then be routed down the tunnel (i.e. out of the virtual
>interface).  This would show up in the LSR MIB out segment.
>
>Cheers,
>Adrian
>----- Original Message -----
>From: "Fang Hao" <fangh@research.bell-labs.com>
>To: <mpls@UU.NET>
>Sent: Friday, July 19, 2002 12:07 PM
>Subject: Question on MIB info for LSP tunneling
>
>
> > Hi-
> >
> > My question is the following:
> > Suppose LSP L1 uses LSP L2 as a tunnel for some intermediate
> > hop between LSR Ru and Rd, is the correlation between L1 and
> > L2 stored somewhere in one of MIBs (MPLS-TE, MPLS-LSR, etc.)
> > of Ru? In other words, if I know the mplsTunnelIndex of L1, can I
> > somehow get to know the mplsTunnelIndex of L2?
> >
> > Could someone shed some light on this?  Thanks.
> >
> > Fang



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