60sec OSPF convergence is pretty bad, and it's not something I'd want to 
achieve.  That said, 100k OSPF routes means you're probably doing something 
wrong.  I would expect any network big enough to have 100k legitimate flowspec 
entries to also have BGP.  Note: the 100k number was Hannes', and I think it's 
awfully high.  

If you really want this to scale you might try to find a distribution method 
that doesn't use AS-scoped LSAs.  Doing this on a campus network means you're 
asking the smallest OSPF devices to handle a ton of information, and I don't 
think that's going to work very well.  Doing this in a PE-CE context means 
you're spreading rules around to lots of places they may not need to be.  For 
example, if you have flowspec routes with specific source addresses and you put 
those routes in parts of the network nowhere near those sources you'll end up 
burning a ton of scarce network resources unnecessarily.  Constraining flowspec 
routes to BGP may mean you don't push them to the edges of the campus and have 
to drop traffic at the campus border router, but that's likely to be the most 
powerful router in the network anwyays.

In his other email, Eric Wu said:

---
My personal experience, for instance, CELCOM from Malaysia and KPN from 
Netherland are using ospf in their networks.
---

Nobody's arguing that OSPF is rare.  My statement was that OSPF *PE-CE* is 
rare; to Peter's point, perhaps less rare than I think, but I still really 
doubt there's much of it when compared to BGP.  I'm also pretty sure that no 
VPN provider wants to open themselves up to carry 100k IGP routes per customer, 
as that's an increase of one or two orders of magnitude in the route counts.  
If everybody does this it takes a large provider's BGP infrastructure from 
millions of routes (doable, but not at zero cost) to hundreds of millions of 
routes.

I think you need to think through the operational consequences of pushing a 
large number of flowspec routes into both the campus IGP and into the 
provider's VPN infrastructure.  Think about efficiency (how do I get the right 
routes to the right places with a link-state protocol?) and about how you 
handle failures (what happens if some nodes in an area can't take all the 
routes?).  I understand the spirit of the draft, and it's hard to argue that 
this sort of DDOS protection is, in spirit, a bad thing.  But I don't think 
that link-state flooding of flowspec routes is the right way to do it.  
Openflow may be better here - push flow policies to only the points that need 
them or can handle them.





eric


-----Original Message-----
From: Youjianjie [mailto:youjian...@huawei.com] 
Sent: Thursday, October 09, 2014 5:24 AM
To: Hannes Gredler; Osborne, Eric
Cc: ospf@ietf.org
Subject: 答复: [OSPF] New Version Notification for 
draft-liang-ospf-flowspec-extensions-01.txt

Hi Hannes,

Usually there're no more than 100K routes in an area. Route advertisement is 
related to the network scale, for directly connected neighbors, OSPF's 
convergence time is about 1 minute for 100K routes. Actually, the signaling for 
FlowSpec routes and IP prefix routes are almost same. FlowSpec routes can be 
seen as more specific routing entries. Furthermore in this document, FlowSpec 
routes are mainly used in DDOS scenarios, instead of replacing the IP prefix 
routes.

Thanks,
Jianjie

-----邮件原件-----
发件人: Hannes Gredler [mailto:han...@juniper.net]
发送时间: 2014年10月8日 23:54
收件人: Osborne, Eric
抄送: Youjianjie; ospf@ietf.org
主题: Re: [OSPF] New Version Notification for 
draft-liang-ospf-flowspec-extensions-01.txt

+1

it would be furthermore interesting to hear from the authors how OSPF behaves 
once a massive scale of flow-routes (lets say in the order of > 100K is 
injected into OSPF).

/hannes

On Wed, Oct 08, 2014 at 03:45:24PM +0000, Osborne, Eric wrote:
| I'm not sure this has much value.  The vast majority of dynamic PE-CE is done 
with BGP; the little bit that isn't BGP is, in my experience, RIP.  I don't 
think I've seen many (any?) OSPF PE-CE deployments.  
| 
| 
| 
| 
| eric
| 
| -----Original Message-----
| From: OSPF [mailto:ospf-boun...@ietf.org] On Behalf Of Youjianjie
| Sent: Tuesday, October 07, 2014 10:11 PM
| To: ospf@ietf.org
| Subject: [OSPF] 转发: New Version Notification for 
| draft-liang-ospf-flowspec-extensions-01.txt
| 
| Hi all,
| 
| This document discusses the use cases that OSPF is used to distribute 
FlowSpec routes. This document also defines a new OSPF FlowSpec Opaque Link 
State Advertisement (LSA) encoding format.
| Your comments are appreciated.
| 
| Best Regards,
| Jianjie
| 
| -----邮件原件-----
| 发件人: internet-dra...@ietf.org [mailto:internet-dra...@ietf.org]
| 发送时间: 2014年9月28日 10:32
| 收件人: Youjianjie; Youjianjie; liuweihang; liuweihang
| 主题: New Version Notification for
| draft-liang-ospf-flowspec-extensions-01.txt
| 
| 
| A new version of I-D, draft-liang-ospf-flowspec-extensions-01.txt
| has been successfully submitted by Jianjie You and posted to the IETF 
repository.
| 
| Name:         draft-liang-ospf-flowspec-extensions
| Revision:     01
| Title:                OSPF Extensions for Flow Specification
| Document date:        2014-09-27
| Group:                Individual Submission
| Pages:                11
| URL:            
http://www.ietf.org/internet-drafts/draft-liang-ospf-flowspec-extensions-01.txt
| Status:         
https://datatracker.ietf.org/doc/draft-liang-ospf-flowspec-extensions/
| Htmlized:       
http://tools.ietf.org/html/draft-liang-ospf-flowspec-extensions-01
| Diff:           
http://www.ietf.org/rfcdiff?url2=draft-liang-ospf-flowspec-extensions-01
| 
| Abstract:
|    This document discusses the use cases why OSPF (Open Shortest Path
|    First) distributing flow specification (FlowSpec) routes is
|    necessary.  This document also defines a new OSPF FlowSpec Opaque
|    Link State Advertisement (LSA) encoding format that can be used to
|    distribute FlowSpec routes.
| 
|    For the network only deploying IGP (Interior Gateway Protocol) (e.g.
|    OSPF), it is expected to extend IGP to distribute FlowSpec routes.
|    One advantage is to mitigate the impacts of Denial-of-Service (DoS)
|    attacks.
| 
| 
|                                                                               
    
| 
| 
| Please note that it may take a couple of minutes from the time of submission 
until the htmlized version and diff are available at tools.ietf.org.
| 
| The IETF Secretariat
| 
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