[j-nsp] VPLS tunnel LSP establishment

[Rafał Szarecki]

2007/8/8, Monika M <monika.vpls at gmail.com>:
>
> I agree with you that router ID configuration is not mandatory to be a
> routable address as per theory. But Don't many vendors mandate using
> Loopback address when it comes to RSVP-TE, static LSP etc....?
>


This is curent best practice, but mandatory.

           Another point: I beleive recursive lookup is no longer required
> for L2VPN NLRI next hop processing as we need to only find out a tunnel LSP
> to the nexthop (Provider edge device for which the PW is  established) and
> not the immediate directly connected nexthop.
>

Indeed. However.
With BGP signaling, BGP Next-Hop is IP address of anouncing PE. Then BGH has
to make lookup for this  IP adres to identyfy LSP.  Thus BGP Next-Hop has to
be an adress with assigned LSP. Consequently to have LSP assigned to adress
route, this adress need to be routable.

Ok. There is potential exception. It is possible to instal route to LSP
(install comand). Of course installed adress can be non-existing on remote
PE. IMHO is like static routing, so this is routable address.

Regards,
> Monika
>
>
> On 8/8/07, Rafał Szarecki <rszarecki at gmail.com> wrote:
> >
> > One comment. ROUTER ID can be, in theory, 4 bytes whch are NOT adress of
> > any interface. Sure best practice and common approche is to have
> > RID==loopback IP. But this is not mandatory.
> >
> > In this generalized case LSP should be established to routable adress.
> > Otherwise BGP will noyt be able to make recursive lookup, as RID do not
> > necesery exist in routing table.
> >
> > 2007/8/2, Erdem Sener <erdems at gmail.com>:
> > >
> > > Monika,
> > >
> > > I would say establishing neighborships, tunnels etc. with router
> > > id's/loopbacks is generally a good idea, unless you need to otherwise
> > > for a very good reason.
> > >
> > > Doing so should not only let you easily use alternate paths between
> > > your P/PE routers as mentioned before but also keep 'clean'
> > > configurations.
> > >
> > > Cheers,
> > > Erdem
> > >
> > > On 8/2/07, Monika M <monika.vpls at gmail.com> wrote:
> > > > Thanks for the response.
> > > > In this case, should I configure the BGP peer address (for l2vpn
> > > signaling)
> > > > also as loopback address?
> > > > (Since tunnel LSP association will be based on the BGP discovered
> > > peer
> > > > address. Not sure whether tunnel LSP will be searched for the
> > > nexthop field
> > > > in the L2VPN NLRI or BGP identifier in the packet.
> > > >
> > > > Regards,
> > > > Monika
> > > >
> > > >
> > > > On 8/2/07, Tomasz Szewczyk < tomeks at man.poznan.pl > wrote:
> > > > >
> > > > > Hi,
> > > > >
> > > > > In my opinion it is much better to use router ID (loopback). You
> > > can
> > > > > experience some problems when using interface address if it goes
> > > down. I
> > > > > assume you have redundant connections/paths between PE1 and PE2.
> > > > >
> > > > > Regards,
> > > > >
> > > > > Tomek
> > > > >
> > > > > Monika M pisze:
> > > > > > site1---PE1 ----- P1-----------P2-----------(x)-PE2----site2
> > > > > >
> > > > > > I have BGP peering between PE1-PE2 for having L2VPN service.
> > > > > > L2VPN configuration steps mandate configuration of tunnel LSP
> > > > > establishment.
> > > > > > Should I have an LSP for the PE2's interface address x or PE2's
> > > router
> > > > > ID.
> > > > > >
> > > > > > TIA
> > > > > > Monika
> > > > > > _______________________________________________
> > > > > > juniper-nsp mailing list juniper-nsp at puck.nether.net
> > > > > > https://puck.nether.net/mailman/listinfo/juniper-nsp
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Tomasz Szewczyk
> > > > > Poznan Supercomputing and Networking Center
> > > > > e-mail: tomeks at man.poznan.pl
> > > > >
> > > > > fax: +48 61 8525954
> > > > >
> > > > >
> > > > _______________________________________________
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> > > >
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> > >
> >
> >
> >
> > --
> > Rafał Szarecki JNCIE-M/T, JNCIP-E
> > +48602418971
>
>
>


-- 
Rafał Szarecki JNCIE-M/T, JNCIP-E
+48602418971