RE: MPLS TE router-id

Hi Rich,

Because the tunnel destination is lo1 on PE2. Every subnets behind the
tunnel will be reachable via the tunnel (in this case PE1 reaches lo0 of PE2
via tunnel). If you don't enable LDP on the tunnel, PE1 doesn't have label
information to reach PE2 lo0.
Since the tunnel is unidirectinal, if you remove label from all physical
interfaces, PE2 doesn't have label information to reach PE1 lo0.
Thus, you just need to enable LDP on the tunnel to solve the problem.
HTH,
Rin.

-----Original Message-----
From: Rich Collins [mailto:nilsi2002_at_gmail.com]
Sent: Wednesday, June 24, 2009 7:42 AM
To: Rin
Cc: Cisco certification
Subject: Re: MPLS TE router-id

Hi Rin,

No I didn't before so I tried it now.

CE1 -- PE1 ---P ---PE2 --CE2 ( I used lo0 on for TE endpoint)

I removed the mpls ip from all the physical interfaces and enabled it
on the tunnel.
I could then ping from CE1 (vrf A interface on PE1) to the opposite
side. Return did not work unless I had another tunnel pointing back.

PE1#sh mpls ldp neighbor

PE1#
PE1#sh mpls interfaces
Interface IP Tunnel Operational
FastEthernet1/0 No Yes Yes
Tunnel0 Yes No Yes
PE1#

If I remove mpls ip under the tunnel it shows:

PE1#sh mpls interfaces
Interface IP Tunnel Operational
FastEthernet1/0 No Yes Yes
Tunnel0 No No Yes
PE1#

The mpls forwarding table appears the same in both cases so I'm not
sure what to look for to see a different behavior.

-Rich

On Mon, Jun 22, 2009 at 9:31 PM, Rin<rintrum_at_gmail.com> wrote:
> Hi Rich,
>
> Did you enable LDP on the tunnel?
> Rin
>
> -----Original Message-----
> From: Rich Collins [mailto:nilsi2002_at_gmail.com]
> Sent: Tuesday, June 23, 2009 3:51 AM
> To: Rin
> Cc: Cisco certification
> Subject: Re: MPLS TE router-id
>
> Yes I was using lo0 for the MP-BGP peering.
>
> On Mon, Jun 22, 2009 at 10:18 AM, Rin<rintrum_at_gmail.com> wrote:
>> Hi Rich,
>>
>> What is you topo? Are you using lo0 for MP-BGP peering?
>> Thanks
>> Rin.
>>
>> -----Original Message-----
>> From: Rich Collins [mailto:nilsi2002_at_gmail.com]
>> Sent: Sunday, June 21, 2009 12:45 AM
>> To: Rin
>> Cc: Cisco certification
>> Subject: Re: MPLS TE router-id
>>
>> Hi Rin,
>>
>> I just tried the bgp vpnv4 routes and noticed that I could not ping
>> through the tunnel when it used loop1.
>>
>>
>> If you try this you see that only one tag is imposed and not two as
>> expected. Perhaps there are other clues why this is not working.
>>
>> PE1#sh ip cef vrf A 45.45.45.0 detail
>> 45.45.45.0/24, version 11, epoch 0
>> 0 packets, 0 bytes
>> tag information set
>> local tag: VPN-route-head
>> fast tag rewrite with
>> Recursive rewrite via 2.2.2.2 0x20, tags imposed {21}
>> via 2.2.2.2, 0 dependencies, recursive
>> next hop 20.2.2.2, Tunnel0 via 2.2.2.2/32
>> valid adjacency
>> tag rewrite with
>> Recursive rewrite via 2.2.2.2 0x20, tags imposed {21}
>>
>>
>> -Rich
>>
>> On Sat, Jun 20, 2009 at 10:39 AM, Rich Collins<nilsi2002_at_gmail.com>
wrote:
>>> Hi,
>>>
>>> I searched the Cisco site and found this:
>>>
>>>
>>
>
http://www.cisco.com/en/US/docs/ios/mpls/configuration/guide/mp_te_expl_addr
>> ess.html
>>> ..........................
>>>
>>> tunnel destination ip-address
>>> Example:
>>>
>>> Router(config-if)# tunnel destination 10.11.11.11
>>>
>>>
>>> Specifies the destination for a tunnel.
>>>
>>> The destination of the tunnel must be the MPLS traffic engineering
>>> router ID of the destination device.
>>>
>>>
>>> -----------------------------
>>>
>>> So in your example you could change the mpls traffic-eng router-id to
>>> lo1 on R3 and it would work. The R1 tunnel source ip address could be
>>> either lo0 or lo1.
>>>
>>> -Rich
>>>
>>> On Fri, Jun 19, 2009 at 5:52 AM, Rin<rintrum_at_gmail.com> wrote:
>>>> Hi group,
>>>>
>>>>
>>>>
>>>> I have this scenario: R1----R2----R3
>>>>
>>>> All routers are in the same area and configured with ISIS. Loopback 0
&
>>>> loopback 1 are created on R1 & R3. All interface are advertised into
> ISIS
>>>> (include lo0 & lo1). I create a MPLS TE tunnel (R1-->R2-->R3) on R1.
The
>>>> MPLS TE router-id is the loopback 0 on each router.
>>>>
>>>> Case 1: If the tunnel source & destination set to lo0, the tunnel is
UP.
>>>>
>>>> Case 2: If the tunnel source & destination set to lo1, the tunnel is
>> DOWN.
>>>>
>>>> My explicit-path pointing to lo0 in case 1 & lo1 in case 2
>>>>
>>>> So what is the relationship between router-id and the source IP,
>>>> destionation of the MPLS TE tunnel?
>>>>
>>>> Thanks.
>>>>
>>>> Rin.
>>>>
>>>>
>>>> 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
Received on Wed Jun 24 2009 - 07:59:52 ART