Re: MPLS forwarding in partial mesh frame-relay networks

Hi Bryan,

Thanks for that clarification.

I was wondering if or how the "targeted LDP sessions (between B&C)"
come into play in this scenario?

-Rich

> On Sat, Jan 23, 2010 at 12:08 AM, Bryan Bartik <bbartik_at_ipexpert.com> wrote:
>>
>> Cool. In case you are wondering how the router might know the next-hop
>> address belongs to the downstream LSR...it is contained in an address
>> mapping message. The LSR basically sends all its interfaces addresses, so
>> the peer can look them up and tell if it can install the label or not. If
>> you do a "show mpls ldp neighor" at the bottom you will see a section called
>> "Addresses bound to peer LDP Ident:"
>>
>> On Fri, Jan 22, 2010 at 11:31 AM, Divin Mathew John <divinjohn_at_gmail.com>
>> wrote:
>>>
>>> Oh.! Thats was something !
>>>
>>> On Fri, Jan 22, 2010 at 11:56 PM, Steve Shaw <shaw38_at_gmail.com> wrote:
>>>>
>>>> Bryan,
>>>>
>>>> Thanks! That's the rule I was looking for.
>>>>
>>>> Steve
>>>>
>>>> On Fri, Jan 22, 2010 at 1:03 PM, Bryan Bartik <bbartik_at_ipexpert.com>
>>>> wrote:
>>>>
>>>> > Rich,
>>>> >
>>>> > An LSR will only install a label for a prefix if the next-hop for that
>>>> > prefix is an address that belongs to the router from which it learned
>>>> > the
>>>> > label. So if Router B's next-hop for Router C is Router C's address,
>>>> > it will
>>>> > not install the label because the label was learned from Router A.
>>>> >
>>>> > What you can do to fix this is install a static route on router B for
>>>> > C's
>>>> > address that points to A as the next-hop. Now the label learned from A
>>>> > will
>>>> > be installed.

Blogs and organic groups at http://www.ccie.net
Received on Fri Jan 22 2010 - 16:44:23 ART