Re: MPLS Aggregate label

Ahh, so the aggregate label is representative of a MPLS layer 3 VPN fec?

Aaron

On Mar 9, 2011, at 2:55 PM, "David Prall" <dcp_at_dcptech.com> wrote:

> Implicit Null, why should the router upstream pop one label and impose
> another when it is destined for the next hop. So instead it does a PHP
> Penultimate Hop Pop. It removes the local label and doesn't push another.
> Saving some resource, most likely very minimal, but just enough to make it
> so that the P router could continue on supporting all the directly connected
> PE's.
>
> Explicit Null's need to be configured so that Null Label is installed.
>
> I believe an aggregate label is a per VRF label, so the PE just advertises a
> single label for all prefixes that belong to that VRF. The receiving PE will
> need to do a local IP lookup to determine which interface the packet needs
> to be forwarded on.
>
> David
>
> --
> http://dcp.dcptech.com
>
>
>> -----Original Message-----
>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
>> Aaron
>> Sent: Wednesday, March 09, 2011 3:44 PM
>> To: 'CCIE KID'; 'Cisco certification'
>> Subject: RE: MPLS Aggregate label
>>
>> Just saw this in my lab today... imp-null seems to have some
>> correlation to
>> connected routes.... perhaps someone can shed some light on this
>> fact/observation...
>>
>> R6#sh mpls ip binding
>> 10.10.10.0/24
>> in label: imp-null
>> 140.100.0.0/27
>> in label: 24
>> 140.100.0.32/27
>> in label: 23
>> 140.100.0.64/28
>> in label: 20
>> 140.100.0.84/30
>> in label: 22
>> 140.100.0.88/30
>> in label: 21
>> 140.100.1.0/24
>> in label: 25
>> 140.100.2.0/24
>> in label: imp-null
>> 140.100.3.0/24
>> in label: imp-null
>> 151.100.0.0/15
>> in label: 34
>> 172.16.0.0/16
>> in label: 26
>> 192.128.128.0/24
>> in label: 19
>> 199.199.1.0/24
>> in label: 29
>> 199.199.2.0/24
>> in label: 28
>> 199.199.3.0/24
>> in label: 27
>> 199.199.4.0/24
>> in label: 33
>> 199.199.5.0/24
>> in label: 32
>> 199.199.6.0/24
>> in label: 31
>> 199.199.7.0/24
>> in label: 30
>> 199.199.8.0/24
>> in label: 18
>> 199.199.9.0/24
>> in label: 17
>> 199.199.10.0/24
>> in label: 16
>> R6#
>> R6#
>> R6#
>> R6#sh ip ro con
>> R6#sh ip ro connected
>> 140.100.0.0/16 is variably subnetted, 8 subnets, 4 masks
>> C 140.100.2.0/24 is directly connected, FastEthernet0/0
>> C 140.100.3.0/24 is directly connected, FastEthernet0/1
>> 10.0.0.0/24 is subnetted, 1 subnets
>> C 10.10.10.0 is directly connected, Ethernet4/0
>> R6#
>>
>>
>> -----Original Message-----
>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
>> CCIE
>> KID
>> Sent: Wednesday, March 09, 2011 5:18 AM
>> To: Cisco certification
>> Subject: MPLS Aggregate label
>>
>> Hey what is the difference between Aggregate label ,implicit null and
>> explicit null label in MPLS
>>
>>
>> --
>> With Warmest Regards,
>>
>> CCIE KID
>> IN PURSUIT OF CCIE
>>
>>
>> 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
>>
>> _______________________________________________________________________
>> 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 Mar 09 2011 - 17:49:15 ART