...and yes, "MPLS encap failed" occurs because of lack of label.
On Mon, Nov 23, 2009 at 11:33 PM, Mirco Orlandi <mirco.orlandi_at_gmail.com>wrote:
> R3 distribute a label for 3.0.0.0/8 (pop tag), but R2 doesn't use it
> because there is a longest match 3.3.3.3/32 (from static)
> The problem is that 3.3.3.3/32 has not remote binding label.
>
> R2#sh mpls ldp bindings 3.0.0.0 255.0.0.0
> tib entry: 3.0.0.0/8, rev 7
> remote binding: tsr: 3.3.3.3:0, tag: imp-null
>
> R2#sh mpls ldp bindings 3.3.3.3 255.255.255.255
> tib entry: 3.3.3.3/32, rev 6
> local binding: tag: 16
>
> When you fix loopback netmask to /32 (or fix static route to /8), BGP
> recursive lookup will find label for next-hop 3.3.3.3
>
> R2#sh mpls ldp bindings 3.3.3.3 255.255.255.255
> tib entry: 3.3.3.3/32, rev 6
> local binding: tag: 16
>
> remote binding: tsr: 3.3.3.3:0, tag: imp-null
>
> I never put attention in this problem, because using of IGP on backbone
> prevents it....
> mirco.
>
>
> On Mon, Nov 23, 2009 at 11:00 PM, Divin Mathew John <divinjohn_at_gmail.com>wrote:
>
>> is the MPLS encapsulation failed error because of the fact that R2
>> fails to get a label from R3 for 3.3.3.3/32 ? so. R2 fails to find a
>> label advertised by R3 for this particular prefix?
>>
>> On Tue, Nov 24, 2009 at 1:59 AM, Bryan Bartik <bbartik_at_ipexpert.com>
>> wrote:
>> > Mirco,
>> >
>> > That's not needed in this case. But you would use that in a
>> > carrier-supporting-carrier scenario where one ISP is using MPLS VPN
>> services
>> > to support an ISP that is also using MPLS.
>> >
>> > It's definitely not for the faint of heart :) but you can try one of
>> > Antonio's scenarios here:
>> >
>> > http://www.ccie18473.net/dynamips/dynamips.htm#csc-cc-mpls
>> >
>> >
>> > On Mon, Nov 23, 2009 at 1:11 PM, Mirco Orlandi <mirco.orlandi_at_gmail.com
>> >wrote:
>> >
>> >> Very good lab to understand better ldp bindings. Thanks.
>> >> but, what about "mpls ip" enabled under (PE)<>(CE) interface?
>> >>
>> >>
>> >> !
>> >> interface FastEthernet0/0
>> >> ip vrf forwarding CA
>> >> ip address 10.1.12.2 255.255.255.0
>> >> mpls ip
>> >> !
>> >>
>> >> I have vrf-aware ldp binding ("show mpls ldp binding vrf CA") but this
>> is
>> >> not a classic MPLS VPN environment.
>> >> Can you suggest a real scenario where make sense?
>> >>
>> >> mirco.
>> >>
>> >>
>> >> On Mon, Nov 23, 2009 at 5:14 AM, Bryan Bartik <bbartik_at_ipexpert.com
>> >wrote:
>> >>
>> >>> Nate,
>> >>>
>> >>> That is a good question. The reason is because you already had a more
>> >>> specific entry in your LIB for 3.3.3.3 (from the static route). If
>> your
>> >>> static routes were pointed at 3.0.0.0/8 and 2.0.0.0/8 then it would
>> work.
>> >>>
>> >>> On Sun, Nov 22, 2009 at 7:37 PM, Nate Lee <natetlee_at_gmail.com> wrote:
>> >>>
>> >>> > Thanks Bryan, that seemed to have solved it. I was under the
>> impression
>> >>> > that I only needed to have a /32 route to the loopback on the local
>> >>> router,
>> >>> > not that the loopback itself had to actually be a /32.
>> >>> >
>> >>> > After doing some reading, it looks like this is because there is no
>> >>> label
>> >>> > on
>> >>> > R2 for 3.3.3.3/32 while one exists for 3.0.0.0/8. Why does it not
>> use
>> >>> the
>> >>> > larger and more inclusive 3.0.0.0/8 label binding which shows the
>> >>> correct
>> >>> > imp-null value to send the packet across?
>> >>> >
>> >>> > From R2:
>> >>> >
>> >>> > tib entry: 3.0.0.0/8, rev 9
>> >>> > remote binding: tsr: 3.3.3.3:0, tag: imp-null
>> >>> >
>> >>> > Thanks again!
>> >>> >
>> >>> > Nate
>> >>> >
>> >>> > On Sun, Nov 22, 2009 at 7:25 PM, Bryan Bartik <bbartik_at_ipexpert.com
>> >
>> >>> > wrote:
>> >>> >
>> >>> > > Nate,
>> >>> > >
>> >>> > > Your loopbacks are /8 so what I guess is happening is R2 is
>> >>> advertising a
>> >>> > > label for 2.0.0.0/8 and R3 is advertising a label for 3.0.0.0/8.
>> This
>> >>> > > prefix does not match what is in your IGP (or static route in your
>> >>> case).
>> >>> > >
>> >>> > > Change the loopbacks to /32 and try it again.
>> >>> > >
>> >>> > > On Sun, Nov 22, 2009 at 6:05 PM, Nate Lee <natetlee_at_gmail.com>
>> wrote:
>> >>> > >
>> >>> > >> I'm hoping that I missed something very simple here, or maybe not
>> >>> since
>> >>> > I
>> >>> > >> have spent an inordinate amount of time trying to figure out what
>> I
>> >>> did
>> >>> > >> wrong.
>> >>> > >>
>> >>> > >> I am just getting started with MPLS VPNs and setup a simple
>> network
>> >>> with
>> >>> > >> R1
>> >>> > >> (CE) <> R2 (PE) <> R3(PE) <> R4 (CE), so no P routers in the mix
>> at
>> >>> all
>> >>> > (I
>> >>> > >> tried it with a P router between the PEs but it didn't work so
>> this
>> >>> is
>> >>> > my
>> >>> > >> stripped down version to help me narrow the problem down).
>> >>> > >>
>> >>> > >> I am running iBGP between R2 and R3 and am redistributing static
>> >>> routes
>> >>> > >> for
>> >>> > >> each CE routers loopbacks on the PE routers as well as
>> redistributing
>> >>> > >> connected into the ipv4 vrf address-family in BGP. Each PE has
>> only
>> >>> a
>> >>> > >> single VRF tied to its CE facing interface.
>> >>> > >>
>> >>> > >> My problem is that I cannot ping from CE to CE or from VRF
>> interface
>> >>> to
>> >>> > >> VRF
>> >>> > >> interface between the PE routers. All routes show up across BGP
>> and
>> >>> > >> populate into the VRF routing tables fine, but when I try to ping
>> >>> from
>> >>> > the
>> >>> > >> VRF interface on R2 to the VRF interface on R3, I get an MPLS
>> >>> > >> encapsulation
>> >>> > >> failed error. I have checked the CEF table, the label bindings
>> and
>> >>> > label
>> >>> > >> forwarding tables and everything looks good.
>> >>> > >>
>> >>> > >> Here is what I get when I do a PING VRF CA 10.1.34.3 so
>> 10.1.12.2.
>> >>> This
>> >>> > >> is
>> >>> > >> R2's CE facing VRF CA interface to R3's CE facing VRF CB
>> interface.
>> >>> > >>
>> >>> > >> *Mar 1 01:30:01.675: IP: s=10.1.12.2 (local), d=10.1.34.3
>> >>> > >> (FastEthernet0/1), len 100, MPLS encapsulation failed
>> >>> > >> *Mar 1 01:30:01.679: ICMP type=8, code=0
>> >>> > >>
>> >>> > >> I am assuming that I am missing something small, but I can't seem
>> to
>> >>> > >> figure
>> >>> > >> out what it is.
>> >>> > >>
>> >>> > >> Here are my configs on R2 and R3:
>> >>> > >>
>> >>> > >> R2:
>> >>> > >>
>> >>> > >> ip vrf CA
>> >>> > >> rd 1:1
>> >>> > >> route-target export 1:100
>> >>> > >> route-target import 1:100
>> >>> > >> !
>> >>> > >> interface Loopback0
>> >>> > >> ip address 2.2.2.2 255.0.0.0
>> >>> > >> !
>> >>> > >> interface FastEthernet0/0
>> >>> > >> ip vrf forwarding CA
>> >>> > >> ip address 10.1.12.2 255.255.255.0
>> >>> > >> mpls ip
>> >>> > >> !
>> >>> > >> interface FastEthernet0/1
>> >>> > >> ip address 10.1.23.2 255.255.255.0
>> >>> > >> mpls ip
>> >>> > >> !
>> >>> > >> router bgp 100
>> >>> > >> no bgp default ipv4-unicast
>> >>> > >> bgp log-neighbor-changes
>> >>> > >> neighbor 3.3.3.3 remote-as 100
>> >>> > >> neighbor 3.3.3.3 update-source Loopback0
>> >>> > >> !
>> >>> > >> address-family ipv4
>> >>> > >> neighbor 3.3.3.3 activate
>> >>> > >> neighbor 3.3.3.3 next-hop-self
>> >>> > >> no auto-summary
>> >>> > >> no synchronization
>> >>> > >> exit-address-family
>> >>> > >> !
>> >>> > >> address-family vpnv4
>> >>> > >> neighbor 3.3.3.3 activate
>> >>> > >> neighbor 3.3.3.3 send-community both
>> >>> > >> exit-address-family
>> >>> > >> !
>> >>> > >> address-family ipv4 vrf CA
>> >>> > >> redistribute connected
>> >>> > >> redistribute static
>> >>> > >> no synchronization
>> >>> > >> exit-address-family
>> >>> > >> !
>> >>> > >> ip forward-protocol nd
>> >>> > >> ip route 3.3.3.3 255.255.255.255 10.1.23.3
>> >>> > >> ip route vrf CA 1.1.1.1 255.255.255.255 10.1.12.1
>> >>> > >>
>> >>> > >> R3:
>> >>> > >>
>> >>> > >> ip vrf CB
>> >>> > >> rd 2:2
>> >>> > >> route-target export 1:100
>> >>> > >> route-target import 1:100
>> >>> > >> !
>> >>> > >> interface Loopback0
>> >>> > >> ip address 3.3.3.3 255.0.0.0
>> >>> > >> !
>> >>> > >> interface FastEthernet0/0
>> >>> > >> ip vrf forwarding CB
>> >>> > >> ip address 10.1.34.3 255.255.255.0
>> >>> > >> mpls ip
>> >>> > >> !
>> >>> > >> interface FastEthernet0/1
>> >>> > >> ip address 10.1.23.3 255.255.255.0
>> >>> > >> mpls ip
>> >>> > >> !
>> >>> > >> router bgp 100
>> >>> > >> no bgp default ipv4-unicast
>> >>> > >> bgp log-neighbor-changes
>> >>> > >> neighbor 2.2.2.2 remote-as 100
>> >>> > >> neighbor 2.2.2.2 update-source Loopback0
>> >>> > >> !
>> >>> > >> address-family ipv4
>> >>> > >> neighbor 2.2.2.2 activate
>> >>> > >> no auto-summary
>> >>> > >> no synchronization
>> >>> > >> exit-address-family
>> >>> > >> !
>> >>> > >> address-family vpnv4
>> >>> > >> neighbor 2.2.2.2 activate
>> >>> > >> neighbor 2.2.2.2 send-community both
>> >>> > >> exit-address-family
>> >>> > >> !
>> >>> > >> address-family ipv4 vrf CB
>> >>> > >> redistribute connected
>> >>> > >> redistribute static
>> >>> > >> no synchronization
>> >>> > >> exit-address-family
>> >>> > >> !
>> >>> > >> ip forward-protocol nd
>> >>> > >> ip route 2.2.2.2 255.255.255.255 10.1.23.2
>> >>> > >> ip route vrf CB 4.4.4.4 255.255.255.255 10.1.34.4
>> >>> > >> !
>> >>> > >>
>> >>> > >>
>> >>> > >> Blogs and organic groups at http://www.ccie.net
>> >>> > >>
>> >>> > >>
>> >>>
>> _______________________________________________________________________
>> >>> > >> Subscription information may be found at:
>> >>> > >> http://www.groupstudy.com/list/CCIELab.html
>> >>> > >>
>> >>> > >>
>> >>> > >>
>> >>> > >>
>> >>> > >>
>> >>> > >>
>> >>> > >>
>> >>> > >>
>> >>> > >
>> >>> > >
>> >>> > > --
>> >>> > > Bryan Bartik
>> >>> > > CCIE #23707 (R&S, SP), CCNP
>> >>> > > Sr. Support Engineer - IPexpert, Inc.
>> >>> > > URL: http://www.IPexpert.com
>> >>> >
>> >>> >
>> >>> > Blogs and organic groups at http://www.ccie.net
>> >>> >
>> >>> >
>> _______________________________________________________________________
>> >>> > Subscription information may be found at:
>> >>> > http://www.groupstudy.com/list/CCIELab.html
>> >>> >
>> >>> >
>> >>> >
>> >>> >
>> >>> >
>> >>> >
>> >>> >
>> >>> >
>> >>>
>> >>>
>> >>> --
>> >>> Bryan Bartik
>> >>> CCIE #23707 (R&S, SP), CCNP
>> >>> Sr. Support Engineer - IPexpert, Inc.
>> >>> URL: http://www.IPexpert.com
>> >>>
>> >>>
>> >>> Blogs and organic groups at http://www.ccie.net
>> >>>
>> >>>
>> _______________________________________________________________________
>> >>> Subscription information may be found at:
>> >>> http://www.groupstudy.com/list/CCIELab.html
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >>
>> >
>> >
>> > --
>> > Bryan Bartik
>> > CCIE #23707 (R&S, SP), CCNP
>> > Sr. Support Engineer - IPexpert, Inc.
>> > URL: http://www.IPexpert.com
>> >
>> >
>> > Blogs and organic groups at http://www.ccie.net
>> >
>> > _______________________________________________________________________
>> > Subscription information may be found at:
>> > http://www.groupstudy.com/list/CCIELab.html
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>>
>>
>>
>> --
>>
>> Sent from Karnataka, India
>> Oscar Wilde - "Arguments are to be avoided; they are always vulgar
>> and often convincing." -
>> http://www.quotationspage.com/quote/23638.html
Blogs and organic groups at http://www.ccie.net
Received on Mon Nov 23 2009 - 23:55:24 ART
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