Re: Question on RFC4873

[Lou Berger <lberger@labn.net>]

Snigdho,

see responses in-line.

At 12:07 PM 9/21/2007, Bardalai, Snigdho wrote:

> Hi,
>
> RFC3473 has specified an option that allows tearing down an LSP 
> using the PathErr message with the Path_State_Removed option. If 
> this option is used in combination with the ADMINSTATUS object with 
> the D and R bits set in the Path message LSPs can be torn down in a 
> graceful manner.
>
> From reading RFC4873 it seems like this option is no longer 
> supported for the segment recovery LSPs. Section 4.2.4.2 in RFC4873 
> requires that when a Path message with D and R bits set is 
> received, a Resv with the D bit set MUST be sent.

I don't see this.  Section 4.2.4.2 only relates to path senders (aka 
"the ingress node").  The draft doesn't limit/modify use of the 
PathErr message with the Path_State_Removed option. (Handling of such 
messages at the recovery LSP ingress is covered in 4.2.1.)

Lou

> What exactly is this addressing? From what I can see there is no 
> strong technical reason to not support PathErr with 
> Path_State_Removed for graceful teardown. Or is there one?
>
> Regards,
> Snigdho