RE: IE Workbook lab 3 Task 2.1 and 4.1

Hi Anthony,

Could you explain this deeper?
The NULL label advertised for the /32 prefix I suppose is the PHP implicit
null. If true, is not advertised for a non /32 prefix?
What is the special label you refer?

Regards and thank you in advance

-----Mensaje original-----
De: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] En nombre de
Anthony Sequeira
Enviado el: martes, 15 de junio de 2010 6:08
Para: Julio Carrasco
CC: ccielab_at_groupstudy.com
Asunto: Re: IE Workbook lab 3 Task 2.1 and 4.1

Hello Julio!

Without the task in front of me, I am going to guess that R4 and R5 are PE
routers in an MPLS L3 VPN scenario. To quote a "Deep Dive" from the very
latest version of our WB II....

"The use of a /32 prefix allows the local router to advertise a NULL label
for the prefix. Any non-host route will generate a special label that the
local router will use to perform an aggregate lookup based on the
destination IP address in the packet. With the NULL label advertisement, the
label lookup will be performed based on the VPNv4 label, in the case of an
MPLS VPN scenario."

Warmest Regards,

Anthony J. Sequeira, CCIE #15626
Senior CCIE Instructor

Test your Tier 1 Knowledge
Q: For RIPng, you can only disable split-horizon ...
A: globally
More Info: http://www.ietf.org/rfc/rfc2080.txt

On Jun 14, 2010, at 10:19 AM, Julio Carrasco wrote:

> Hello experts,
> I am reviewing this lab, and I saw, that on Task 2.1 it says that is
necessay
> for Lo0 on R4 and R5, to be announced with a mask of 32 bits, so the LDP
> peering on task 4.1 needs both loopbacks to be a /32 mask.
> I do not understand exactly why, so could anyone please help me with that
?
>
> Thanks in advance and best regards !!!!
>
>
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Received on Tue Jun 15 2010 - 11:00:51 ART