The MPLS WG Archive

[Curtis Villamizar <curtis@fictitious.org>]

In message <F69EB380D594D611BBEA00065B3F14B4A3525A@MAIL>, Steve Yao writes:
> 
> 
> >It wasn't intended to cover all cases and does not depricate use of
> >path-tear.  You still didn't answer my question.
> 
> But it is ok if you don't want to answer the question.


OK.  I wasn't trying to avoid a question, just lost track of which
question you were referring to.  There are a couple of cases.

The topic of running MPLS with an external path computation and
explicitly configured paths comes up from time to time.  Some carriers
claim they'd do this without running an IGP at all.  I don't know of
anyone that has successfully done this and I personnally think it is a
very bad idea but MPLS with explicitly configured paths and no IGP
running is a supported feature for many LSR anyway.

In inter-area MPLS, if hierarchical LSP were not used, the ingress
would set up paths across areas not it would not be notified of links
that went down in other areas.  Not running hierarchical LSP in this
case is probably not very scalable and creates this problem as well
but that network design issue is a matter of best practices.  The LSR
should "do the right thing" even if the network design is poor.

Those were the types of cases I was thinking of.

Curtis