Re: [nsp] MPLS Traffic engineering

From: dhudson (dhudson@pilot.net)
Date: Tue Nov 07 2000 - 12:19:40 EST


oh, yeah...
i forgot about the need for a link-state protocol.
all the more reason for #7 below...

piranha...we dont use nets but we do like dolphin...

dhudson wrote:
>
> Eric Osborne wrote:
> >
> >
> > > What about iBGP? I know somebody who succefully running MPLS network using
> > > only iBGP as IGP. Sure, it requires careful network design and addressing
> > > planning, but it pays off by actually working. ;) Please correct me if I'm
> > > wrong somewhere.
> > >
> >
> > MPLS-TE (Traffic Engineering) needs a link-state IGP.
> > MPLS forwarding based on LDP/TDP (whether or not you run VPNV4BGP on
> > top of that) doesn't care what your IGP is, although personally I have
> > my objections to using iBGP as an IGP...:)
> >
> > eric
>
> i think running iBGP as an IGP has some major drawbacks.
>
> 1. it is meant to tell other iBGP speakers about the best pathway
> OUT of the AS not really optimal for internal navigation.
>
> 2. if you arent fully meshed, then you are running in a degraded fashion.
>
> 3. it converges on an order of magnitude slower than any of the IGPs.
>
> 4. you violate the first cardinal tenant of when to use any BGP
> if you have any stub nets with a single entry/exit point.
>
> 5. because the iBGP speakers must communicate with eBGP, it creates the
> potential for allowing an external AS alter your routing policy.
>
> 6. if you are connected with an ISP and your internal policy is the same
> as theres, BGP shouldnt even be running at all. statics and defaults
> are cleaner.
>
> 7. why when you have OSPF...
>
> piranha...lurk whether we are hungry or not...
>
> --
>
> ---------------------------------------------------
> my lord tzu, running away is the first martial tao
> archery sifu to sun tzu
> ---------------------------------------------------

-- 

--------------------------------------------------- my lord tzu, running away is the first martial tao archery sifu to sun tzu ---------------------------------------------------



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