[c-nsp] forced path MPLS tunnel question

[Gert Doering]

Hi,

On Tue, Jan 17, 2012 at 03:48:49PM +0000, Chris Mason wrote:
> When you enable RSVP and TE on an interface, certain characteristics
> of the interface are included within ISIS LSP (e.g. bandwidth being
> the simplest).
> 
> When you create a tunnel on a head end router it will use something
> called CSPF (Constrained Shortest Path First) to find a path through
> your network which matches the constraints you have defined on the
> logical tunnel interface (i.e. minimum bandwidth of 100k) - it uses
> the extra information in the LSP to work this out. When it has
> computed a viable path, it uses RSVP to signal the tunnel using Path
> messages.

*This* was what I was missing - "what happens behind the scenes?".  Thanks!

> Basically, you need OSPF or ISIS with RSVP and MPLS TE enabled on
> every interface you want the tunnel to traverse.

For the "verbatim!" paths, having the point-to-point next-hops listed
(and having "mpls traffic-eng tunnels" on the interface) seems to be 
sufficient - it's now working for a somewhat smaller-than-planned
test rig, but it *is* working :-)  (and I have learned something).

So thanks to all who answered and helped.

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
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 305 bytes
Desc: not available
URL: <https://puck.nether.net/pipermail/cisco-nsp/attachments/20120117/e6e91f8f/attachment.sig>