Re: [Idr] draft-asati-idr-bgp-bestpath-selection-criteria as IDR WG draft

["Ilya Varlashkin" <Ilya.Varlashkin at de.easynet.net>]

> -----Ursprüngliche Nachricht-----
> Von: idr-bounces at ietf.org [mailto:idr-bounces at ietf.org] Im 
> Auftrag von Robert Raszuk
> Gesendet: Donnerstag, 23. Juli 2009 09:13
> An: curtis at occnc.com
> Cc: idr List
> Betreff: Re: [Idr] 
> draft-asati-idr-bgp-bestpath-selection-criteria as IDR WG draft
> 
> Hi Curtis,
> 
> I think your assessment of the draft is right. The original 
> issue has been raised by the problem of considering next hop 
> as valid and reachable IP reachability wise without any 
> correlation with MPLS LSP to such next hop which was a must 
> and a prerequisite for some applications to work.
> 
> In my opinion this is a valid problem, but this is not a BGP issue.
> 
> Underlying transport (for example MPLS LDP or MPLS-TE) should 
> only expose valid and reachable LSPs to it's RIB so when BGP 

Robert,

in some scenarios (e.g Inter-AS MPLS stuff) labels are distributed by BGP itself. Also, LDP may have received all correct info from the neighbors, but failed to install it into forwarding plane (either due to hardware failure or a software bug). Having experienced this with routers from two different manufacturers, I believe it would be really benefical if BGP could perform a bit more extended checks rather than just looking into control plane. I understand that issue is more of "local type" (e.g. hardware failure) rather than protocol itself, but considering reality (bugs do happen and hardware does fail) it's very desirable that BGP specs at least encourage implementors to make more effort in validating next-hop. And this is why I believe IDR is correct WG for this draft.

Cheers,
iLya