The MPLS WG Archive

[Robert Raszuk <raszuk@cisco.com>]

Hi Sachin,

> Because it just look at the bottom label of the packet,
> and as per the entries into its VRF table, PE2 just sends out the packet to
> CE11.

PE2 should based on the information retrived from the VPN label do the
vrf lookup which reveals that the packet is destined to itself. There is
no need to send it to CE11. 

R.

> Sachin Kalra wrote:
> 
> Dear MPLS Community:
> 
> I would appreciate if someone can answer the following question about
> BGP-MPLS VPNs.
> 
> Lets say we have the following topology:
> 
> [CE1]                                                             [CE11]
>          \                                                           /
>          [PE1]-----------------[Rtr1]-------------------[PE2]
>          /                                                           \
> [CE2]                                                             [CE22]
> 
> 1. PE and CEs have static routes configured between each other. i.e. no
> routing protocol running on the interfaces connecting PEs and CEs.
> 
> Question. How will a packet going from CE1 and destined to interface on PE2
> (that connects PE2 and CE11) reach its destination?
> 
> The problem is that when PE2 receives a packet destined to its out
> interface connecting "PE2->CE11". PE2 does not know that the packet is
> destined to itself. Because it just look at the bottom label of the packet,
> and as per the entries into its VRF table, PE2 just sends out the packet to
> CE11.
> 
> Is this the correct behavior?
> 
> I appreciate your response.
> Thanks,
> Sachin Kalra