The MPLS WG Archive

["Sharma, Prem" <p_sharma@trillium.com>]

Title: RE: Valid Race Condition related to draft "draft-ietf-mpls-crlsp-modify-03.txt"

Hi Don,

 

But what about the cases when you have loose hops in the explicit routes and route pinning is not requested? Can there be a scenario where the arrival of a next hop change trigger (for a loosely routed hop), while the original LSP is being re-routed, may potentially lead to race condition?

 

Thanks.

Prem

 

 

 -----Original Message-----
From: Don Fedyk [mailto:dwfedyk@nortelnetworks.com]
Sent: Monday, March 26, 2001 6:12 AM
To: manoj juneja; mpls@UU.NET
Cc: gash@att.com; Peter Ashwood-Smith; Bilel Jamoussi; fedyk@nortelnetworks.com; skalecki@nortelnetworks.com; lili@ss8networks.com; ylee@irislabs.com
Subject: RE: Valid Race Condition related to draft "draft-ietf-mpls-crlsp -modify-03.txt"

Manoj

Usually the path modification is for TE LSP that are routed via an Explicit route. This means that they are not affected by next hop changes in IP routing. If the existing path is torn down due to a failure on the path then you have a couple of options.

1. Abort any modification and treat as a normal failure.
2. Handle the path release but wait for the new modification path in hope that it will still be valid.

We have built 1. in the past. 2. is more difficult and a low percentage success rate.

Don

> -----Original Message-----
> From: manoj juneja [mailto:manojkumarjuneja@hotmail.com]
> Sent: Wednesday, March 21, 2001 6:06 PM
> To: mpls@UU.NET
> Cc: gash@att.com; Ashwood-Smith, Peter [CAR:CS0I:EXCH];
> Jamoussi, Bilel
> [BL60:2868-M:EXCH]; fedyk@nortelnetworks.com;
> skalecki@nortelnetworks.com; lili@ss8networks.com; ylee@irislabs.com
> Subject: Valid Race Condition related to draft
> "draft-ietf-mpls-crlsp-modify-03.txt"
>
>
> Hi All,
>
>    Please comment on the following :
>
>         If the LSP modification is in progress and in the meantime the
> next hop for the same LSP changes then should the modification
> procedure be aborted ?
>
> Regards,
> manoj.
>
>
>
>
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