[mpls-linux-general] Re: Route Alert Option

[James R. L. <jl...@mi...>]

As far as I know, no one uses the "router alert" label.  It was originally
added to the MPLS encoding spec as a "just in case" type of measure.

What is the correct behavior for a IP packet with the router alert bit
set?  How does the IP stack know "who" to locally deliver it to?  If you
can answer these questions then your further along the path to understanding
what the router alert label should do  then I am :-)

On Tue, Sep 25, 2001 at 06:29:18PM +0530, Rajesh P Jain wrote:
> "Hi",
>                 I have 2 questions on IP Route Alert Options (and , Of
> course corresponding to the MPLS Route Alert Label (LABEL Value 1)).
> 
> 1.    When a  LSR receives a Labelled packet with a value of 1, what is
> the treatment given to that labelled packet. (In the diagram LSR).
> 
> 2.     When an Ingress Node (In the Diagram LER A), when an IP Packet
> comes with IP Route Alert Option, How is the MPLS labels that packet ??
> I mean, does it label it with a value of 1 or does it look into the LIB
> for the corresponding destination address of the packet ???
> 
>                         Please throw light on these questions and
> clarify how does source-forge linux MPLS forwarding Engine (JRL's
> Implementation) treats the above 2 cases.
> 
> LER A --------- LSR ------------- LER B
> 
> TIA
>         Rajesh P Jain

-- 
James R. Leu