Re: Next HOP on IBGP

No worries :) I noticed my response to his question from the other day was
blank.

Steve Lyons

On Thu, Aug 20, 2009 at 11:34 PM, Narbik Kocharians <narbikk_at_gmail.com>wrote:

> Steve i totally mis-read the question, i am sorry. I must have been very
> tired.
>
>
> On Thu, Aug 20, 2009 at 8:22 PM, Steve Lyons <charter21p5_at_gmail.com>wrote:
>
>> I tried to respond to your question the other day and had browser issues.
>> My understanding is you are asking why in a MPLS VRF is the next hop the PE
>> routers and not the source CE routers? If this is your question the reason
>> why this is required is because MPLS routers use a dual stack (outer and
>> inner) label in LDP/TDP. The outer label is source PE router advertising the
>> prefix and the inner label is the prefix within the VRF. This is not the
>> same scenario for non-mpls BGP networks such as a EBGP connection to an ISP
>> for internet and then IBGP connections to an internal LAN.
>>
>> Steve Lyons
>>
>> On Wed, Aug 19, 2009 at 11:24 PM, Narbik Kocharians <narbikk_at_gmail.com>wrote:
>>
>>> May be the link is advertised in the IGP that you are running between R1
>>> and R2. Some times its recommended to do that with a passive-interface to
>>> provide reachability.
>>>
>>>
>>> On Wed, Aug 19, 2009 at 8:12 PM, Steve Lyons <charter21p5_at_gmail.com>wrote:
>>>
>>>> On Tue, Aug 18, 2009 at 5:12 AM, Mark Stephanus Chandra <
>>>> mark.chandra_at_gmail.com> wrote:
>>>>
>>>> > Dear GS,
>>>> >
>>>> >
>>>> >
>>>> > I have something weird going on,
>>>> >
>>>> >
>>>> >
>>>> > This is my network topology
>>>> >
>>>> >
>>>> >
>>>> > R1(AS 65000)-------R2(AS65001) ------R3(AS65001)
>>>> >
>>>> >
>>>> >
>>>> > So R1 have eBgp connection to R2 and R2 and R3 have iBGP connection.
>>>> >
>>>> >
>>>> >
>>>> > The Theory is, if R2 have routing update from R1, then the nexthop is
>>>> R1
>>>> > and
>>>> > the update continue to R3 but cause of this iBGP Connection, the next
>>>> hop
>>>> > will not change and still to R1.
>>>> >
>>>> >
>>>> >
>>>> > But Now, in one of my customer network, I can see route update that
>>>> come
>>>> > form R1, from R3 perspective the nexthop is change to R2, and in R2
>>>> I'm not
>>>> > configured Next-hop-Self.
>>>> >
>>>> >
>>>> >
>>>> > Have anyone experiencing the same like I do ?
>>>> >
>>>> >
>>>> >
>>>> > IOS bug ?
>>>> >
>>>> >
>>>> >
>>>> > FYI, this is all inside the same VRF
>>>> >
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > Regards
>>>> >
>>>> > Mark Stephanus Chandra - CCIE#23887
>>>> >
>>>> >
>>>> > Blogs and organic groups at http://www.ccie.net
>>>> >
>>>> >
>>>> _______________________________________________________________________
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>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Narbik Kocharians
>>> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
>>> www.MicronicsTraining.com <http://www.micronicstraining.com/>
>>> Sr. Technical Instructor
>>>
>>
>>
>
>
> --
> Narbik Kocharians
> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> www.MicronicsTraining.com <http://www.micronicstraining.com/>
> Sr. Technical Instructor

Blogs and organic groups at http://www.ccie.net
Received on Thu Aug 20 2009 - 23:42:51 ART