From: DENNIS UBOM (cciedreamz@gmail.com)
Date: Wed Nov 26 2008 - 06:34:35 ARST
Guys,
if you running a network with both LDP/RSVP TE with services like MPLS
VPN, MVPN, MPLS QOS etc.
let say a network with RSVP TE PE-PE and LDP is enabled all the way down
also from PE-PE.
how can you tell which signalling is being used? RSVP OR LDP? I have a
network running both and even targeted LDP on TE, been thinking about
removing LDP.
Also what should i be aware of before removing LDP session from production?
Are there any benefit running Both LDP and RSVP?
Thanks
Dennis
On Wed, Nov 26, 2008 at 2:20 AM, Jian Gu <guxiaojian@gmail.com> wrote:
> Roman,
>
> The command "mpls traffic-eng multicast intact" was introduced* *to enable
> interoperability between* *Protocol-Independent Multicast (PIM) and
> Multiprotocol Label Switching (MPLS) traffic engineering, it has nothing to
> do with MDT RPF check, it is introduced before mVPN is available.
>
> There are 3 RPF check happens in mVPN, 1) C-packets received from a PE
> router customer interface in mVRF; 2) P-ackets received from a PE router or
> P router interface in the global routing table; and 3)C-Packets received
> from MTI (multicast tunnel interface) in mVRF
>
> RPF check 1) is straightforwad.
>
> For RPF check 2), if MPLS TE tunnel is next hop between PEs, yes, you will
> need this command to make RPF check pass, but note that it is not a
> necessity to have MPLS TE tunnel as IGP next hop between PEs, in fact, the
> whole mVPN does not depend on MPLS at all (only PIM SM register/register
> stop messages will ride on existing MPLS transport)
>
> For 3) IOS has internally changed the RPF check requirements such that if
> MBGP has learned a prefix that contains C-source address, the RPF inteface
> is set to MTI that is associated with that mVRF and RPF neighbor is also
> modified to be the remote PE router,
>
> So you see, MDT has nothing to do with "mpls traffic-eng multicast intact".
>
> Jian
>
> P.S. I highly doubt that OP is doing MDT though.
>
> On Tue, Nov 25, 2008 at 7:41 PM, Roman Rodichev <roman@iementor.com>
> wrote:
>
> > When a multicast IP packet is received, IOS will perform RPF check on the
> > source of the multicast packet to make sure it arrived on the correct
> > interface. MDT tunnels are sourced from loopback interfaces, same
> loopbacks
> > that are reachable via the TE tunnels. MDT tunnel packets destination is
> > multicast. So when a PE receives an MDT packet on a physical interface,
> it
> > does an RPF check and says "Oh, this source is supposed to arrive on this
> > TE
> > tunnel interface" and multicast breaks. That command fixes the problem
> >
> >
> > Roman Rodichev
> > 5xCCIE #7927 (R&S, Security, Voice, Storage, Service Provider)
> > Instructor, Content Developer
> > ieMentor Corporation http://www.iementor.com
> > Y!M: roman7927
> >
> >
> > -----Original Message-----
> > From: Vin Mendoza (vinm) [mailto:vinm@cisco.com]
> > Sent: Tuesday, November 25, 2008 9:37 PM
> > To: Roman Rodichev; mreiks
> > Cc: Cisco certification; Cisco certification
> > Subject: RE: MPLS TE + RSVP+LDP
> >
> > What does multicast-intact do?
> >
> > Vin
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > Roman Rodichev
> > Sent: Tuesday, November 25, 2008 10:20 PM
> > To: 'mreiks'
> > Cc: 'Cisco certification'; 'Cisco certification'
> > Subject: RE: MPLS TE + RSVP+LDP
> >
> > You are doing MDT?
> >
> >
> >
> > under router ospf or router isis in the core put:
> >
> >
> >
> > mpls traffic-eng multicast-intact
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Roman Rodichev
> >
> > 5xCCIE #7927 (R&S, Security, Voice, Storage, Service Provider)
> >
> > Instructor, Content Developer
> >
> > ieMentor Corporation http://www.iementor.com
> >
> > Y!M: roman7927
> >
> >
> >
> > From: mreiks [mailto:marakalas.molefe@gmail.com]
> > Sent: Tuesday, November 25, 2008 9:15 PM
> > To: Roman Rodichev
> > Cc: Cisco certification; Cisco certification
> > Subject: Re: MPLS TE + RSVP+LDP
> >
> >
> >
> > Hmm, my excitement was short-lived there. Now my multicast tunnel
> > between the two PE routers is broken after disabling "mpls ip" on the
> > interfaces.
> > Any idea?
> >
> > On Wed, Nov 26, 2008 at 5:12 AM, mreiks <marakalas.molefe@gmail.com>
> > wrote:
> >
> > Wow, tx a lot Roman, it's working now without "mpls ip" on the SP
> > interfaces. I only had the TE tunnel configured only on the one PE. Much
> > appreciated.
> >
> >
> >
> > On Wed, Nov 26, 2008 at 4:38 AM, Roman Rodichev <roman@iementor.com>
> > wrote:
> >
> > Hello,
> >
> > You don't need LDP in order to run MPLS VPN over TE tunnels. When you
> > say you "disable LDP on the interfaces", I assume you are disabling
> > "mpls ip" on the physical interfaces. In a simple CE1 - PE1 - P - PE2 -
> > CE2 network, make sure you have a TE tunnel from PE1 to PE2 and from PE2
> > to PE1. Make sure you are using "tunnel mpls traff autoroute announce"
> > so that PE1 and PE2 loopbacks are reachable via TE tunnels instead of
> > the IGP path. You can remove LDP between PE1, P and PE2 router, and your
> > MPLS L3VPN will work.
> >
> > By the way, you don't need "mpls ip" on the TE tunnel interfaces if
> > their headends and tailends are on PE routers (not on P routers).
> >
> > If you have a specific scenario, please present.
> >
> > Roman Rodichev
> > 5xCCIE #7927 (R&S, Security, Voice, Storage, Service Provider)
> > Instructor, Content Developer ieMentor Corporation
> > http://www.iementor.com
> > Y!M: roman7927
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > mreiks
> > Sent: Tuesday, November 25, 2008 2:37 PM
> > To: Cisco certification; Cisco certification
> > Subject: MPLS TE + RSVP+LDP
> >
> > Hi
> >
> > I am finding it diffucult to understand whether RSVP TE can be run
> > instead of LDP/TDP. I am able to establish the tunnel with TE but when I
> > disable LDP on the interfaces, my VPN sites cannot ping each other,
> > until such time I enable LDP. Is this normal? With MPLS VPNs do we
> > always have to run either LDP/TDP and have RSVP also if we want TE?
> >
> > Tx.
> >
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
> >
> > _____________________________________________________________________
> > Subscription information: http://www.groupstudy.com/list/comserv.html
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
Blogs and organic groups at http://www.ccie.net
This archive was generated by hypermail 2.1.4 : Mon Dec 01 2008 - 08:18:32 ARST