Re: vpn label understanding required

Anytime! :)

On Thu, Jun 25, 2009 at 11:22 AM, jack daniels <jckdaniels12_at_gmail.com>wrote:

> Thanks Bryan :)
> got it
> Regards
> J.Daniels
> On Thu, Jun 25, 2009 at 10:49 PM, Bryan Bartik <bbartik_at_ipexpert.com>wrote:
>
>> This is the LFIB, once the router has assigned a label it will not re-use
>> it. That's why they call it a per-platform label space.
>>
>>
>> On Thu, Jun 25, 2009 at 11:12 AM, jack daniels <jckdaniels12_at_gmail.com>wrote:
>>
>>> Hi,
>>>
>>>
>>> sh mpls forwarding-table detail
>>> Local Outgoing Prefix Bytes Label Outgoing Next Hop
>>> 21 No Label 150.1.7.7/32[V] <http://150.1.7.7/32%5BV%5D>
>>> 0 Fa0/0 10.1.37.7 <<<<<<<<<<<<<<
>>> Local Outgoing Prefix Bytes Label Outgoing Next
>>> Hop
>>> Label Label or VC or Tunnel Id Switched
>>> interface
>>> MAC/Encaps=0/0, MRU=1504, Label Stack{}
>>> VPN route: SW1-BB1
>>>
>>> Is that VPN LABEL 21 will be there on the packet once it reaches this
>>> router and it sees
>>>
>>> VPN route: SW1-BB1 and Fa0/0 10.1.37.7 .... Based on this it
>>> forwards the packet.
>>> BUT NOW A NEW Q ARISES - I m sorry for that , what makes router keep in
>>> record it has already given 21 label to a prefix, don't use it.
>>>
>>> Regards
>>> J.Daniels
>>>
>>>
>>> On Thu, Jun 25, 2009 at 10:21 PM, Bryan Bartik <bbartik_at_ipexpert.com>wrote:
>>>
>>>> Jack,
>>>>
>>>> "Show mpls forwarding-table detail" shows the label, prefix and the VRF.
>>>>
>>>>
>>>>
>>>> On Thu, Jun 25, 2009 at 10:43 AM, jack daniels <jckdaniels12_at_gmail.com>wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> If that is the case , so router must be keeping a database of label to
>>>>> VRF , how can we see that ....( command)
>>>>>
>>>>> Regards
>>>>> J.Daniels
>>>>>
>>>>> On Thu, Jun 25, 2009 at 10:01 PM, Bryan Bartik <bbartik_at_ipexpert.com
>>>>> > wrote:
>>>>>
>>>>>> Yes, that is right.
>>>>>>
>>>>>>
>>>>>> On Thu, Jun 25, 2009 at 10:25 AM, jack daniels <
>>>>>> jckdaniels12_at_gmail.com> wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> so it means LFIB lookup is done , which sees [V] VPN label and
>>>>>>> forwards to the appropriarate VRF. so if a router has 200 VRF and each VRF
>>>>>>> is orignating 2 routes so it means 400 UNIQUE LABELS will identify which VRF
>>>>>>> to forward the traffic.
>>>>>>>
>>>>>>> Regards
>>>>>>> J.daniels
>>>>>>>
>>>>>>> On Thu, Jun 25, 2009 at 9:28 PM, Bryan Bartik <
>>>>>>> bbartik_at_ipexpert.com> wrote:
>>>>>>>
>>>>>>>> Jack,
>>>>>>>>
>>>>>>>> I see what you mean, good question. If you so "show mpls
>>>>>>>> fowarding-table detail" you will see the VPN. I think this would be a
>>>>>>>> function of looking up the label in the LFIB when the prefix is listed with
>>>>>>>> [V].
>>>>>>>>
>>>>>>>>
>>>>>>>> On Thu, Jun 25, 2009 at 9:47 AM, jack daniels <
>>>>>>>> jckdaniels12_at_gmail.com> wrote:
>>>>>>>>
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> I got that but my querrie still stands - let me put it other way
>>>>>>>>>
>>>>>>>>> ( 1.1.1.0/24)CE1--VRF <http://1.1.1.0/24%29CE1--VRF>K--PE1----P1----PE2----CE2
>>>>>>>>> packet from CE2 reaches PE1 with VPN label , now what will hapen
>>>>>>>>> .... will router say it has stamp of label Y which is for VRF X ?
>>>>>>>>>
>>>>>>>>> Regards
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Thu, Jun 25, 2009 at 8:45 PM, Bryan Bartik <
>>>>>>>>> bbartik_at_ipexpert.com> wrote:
>>>>>>>>>
>>>>>>>>>> Jack,
>>>>>>>>>>
>>>>>>>>>> Yes, each prefix learned in the VRF would have a different label.
>>>>>>>>>> I would not associate labels with VRFs, but rather with the prefix learned
>>>>>>>>>> in the VRF. The bottom label corresponds to the egress PE, the inner label
>>>>>>>>>> corresponds to the prefix in the VRF.
>>>>>>>>>>
>>>>>>>>>> On Thu, Jun 25, 2009 at 7:06 AM, jack daniels <
>>>>>>>>>> jckdaniels12_at_gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> Hi group,
>>>>>>>>>>>
>>>>>>>>>>> I have routers
>>>>>>>>>>>
>>>>>>>>>>> ( 1.1.1.0/24)CE1--VRF <http://1.1.1.0/24%29CE1--VRF>K--PE1----P1----PE2----CE2
>>>>>>>>>>>
>>>>>>>>>>> now when pkt is forwarded from CE2 for 1.1.1.0/24 it has VPN
>>>>>>>>>>> label Y. On
>>>>>>>>>>> reaching PE1 it sees label Y = VRF K....
>>>>>>>>>>> so it means that if a router has 2000 vrf on it , so it will
>>>>>>>>>>> asign unique
>>>>>>>>>>> labels per vrf for each prefix to advertise in vrf ?
>>>>>>>>>>>
>>>>>>>>>>> Regards
>>>>>>>>>>> J.Daniels
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Blogs and organic groups at http://www.ccie.net
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> _______________________________________________________________________
>>>>>>>>>>> Subscription information may be found at:
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>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Bryan Bartik
>>>>>>>>>> CCIE #23707 (R&S), CCNP
>>>>>>>>>> Sr. Support Engineer - IPexpert, Inc.
>>>>>>>>>> URL: http://www.IPexpert.com <http://www.ipexpert.com/>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Bryan Bartik
>>>>>>>> CCIE #23707 (R&S), CCNP
>>>>>>>> Sr. Support Engineer - IPexpert, Inc.
>>>>>>>> URL: http://www.IPexpert.com <http://www.ipexpert.com/>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Bryan Bartik
>>>>>> CCIE #23707 (R&S), CCNP
>>>>>> Sr. Support Engineer - IPexpert, Inc.
>>>>>> URL: http://www.IPexpert.com <http://www.ipexpert.com/>
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Bryan Bartik
>>>> CCIE #23707 (R&S), CCNP
>>>> Sr. Support Engineer - IPexpert, Inc.
>>>> URL: http://www.IPexpert.com <http://www.ipexpert.com/>
>>>>
>>>
>>>
>>
>>
>> --
>> Bryan Bartik
>> CCIE #23707 (R&S), CCNP
>> Sr. Support Engineer - IPexpert, Inc.
>> URL: http://www.IPexpert.com <http://www.ipexpert.com/>
>>
>
>

-- 
Bryan Bartik
CCIE #23707 (R&S), CCNP
Sr. Support Engineer - IPexpert, Inc.
URL: http://www.IPexpert.com
Blogs and organic groups at http://www.ccie.net