RE: About the WG adoption of draft-xu-l3vpn-virtual-subnet-fib-reduction-00

[Xuxiaohu <[e-mail]>]

Hi Wim,

Great. How about adding the following text somewhere in the draft:

"If one or more particular remote host routes need to be installed by default for whatever reasons, the best way to realize such goal is to attach a special extended community attribute to those particular host routes by originating PE routers or route reflectors. Upon receiving any host routes attached with the above extended community attribute, non-APR PE routers would install them by default"

Of course, it would be much appreciated if you could provide some text.

Best regards,
Xiaohu

> -----Original Message-----
> From: Henderickx, Wim (Wim) [mailto:[e-mail]]
> Sent: Wednesday, July 30, 2014 6:11 PM
> To: Xuxiaohu; [e-mail]
> Subject: Re: About the WG adoption of
> draft-xu-l3vpn-virtual-subnet-fib-reduction-00
> 
> See right now there is /32 or /128 routes which can come from hosts in virtual
> subnet/CE-PE protocol/static routes/loopbacks/etc and to figure out the origin
> you have very little means doing so. So if an operator wants to distinguish the
> installation by default in the FIB it would be good to tag the origin and he can
> than decide based on local policy what to do. I believe it is a good practice and
> should be described in the draft.
> 
> This is what I meant to say
> 
> On 30/07/14 11:48, "Xuxiaohu" <[e-mail]> wrote:
> 
> >Hi Wim,
> >
> >I just want to figure out in which scenario the host route to the VRF
> >interface address of a remote PE router should be FIB-installed by
> >default. If there is a scenario, I agree that your proposal of using
> >communities is the best way.
> >
> >Best regards,
> >Xiaohu
> >
> >> -----Original Message-----
> >> From: Henderickx, Wim (Wim)
> >> [mailto:[e-mail]]
> >> Sent: Wednesday, July 30, 2014 5:37 PM
> >> To: Xuxiaohu; [e-mail]
> >> Subject: Re: About the WG adoption of
> >> draft-xu-l3vpn-virtual-subnet-fib-reduction-00
> >>
> >> In that case you can argue why not do it for all routes as well.
> >>
> >> On 30/07/14 11:30, "Xuxiaohu" <[e-mail]> wrote:
> >>
> >> >Why do you need to distinguish them from each other? In other words,
> >> >why can't PE routers process the host route to a given VRF loopback
> >> >address of a remote PE router as a normal remote host route (i.e.,
> >> >on-demand installation)?
> >> >
> >> >Best regards,
> >> >Xiaohu
> >> >
> >> >-----Original Message-----
> >> >From: Henderickx, Wim (Wim)
> >> >[mailto:[e-mail]]
> >> >Sent: Wednesday, July 30, 2014 5:20 PM
> >> >To: Xuxiaohu; [e-mail]
> >> >Subject: Re: About the WG adoption of
> >> >draft-xu-l3vpn-virtual-subnet-fib-reduction-00
> >> >
> >> >Why not, if I configure a loopback in the VRF it has to be
> >> >advertised, this is generic VRF functionality, nothing to do with
> >> >virtual subnet. I am not talking to the IP address on the virtual subnet
> interface.
> >> >In this case you need to distinguish between host routes and these
> >>VRFs.
> >> >Using communities is the best way afais.
> >> >
> >> >On 30/07/14 10:59, "Xuxiaohu" <[e-mail]> wrote:
> >> >
> >> >>Hi Wim,
> >> >>
> >> >>In the Virtual Subnet context, the host route corresponding to the
> >> >>VRF interface address doesn't need to be advertised.
> >> >>
> >> >>Best regards,
> >> >>Xiaohu
> >> >>
> >> >>> -----Original Message-----
> >> >>> From: Henderickx, Wim (Wim)
> >> >>> [mailto:[e-mail]]
> >> >>> Sent: Wednesday, July 30, 2014 4:55 PM
> >> >>> To: Xuxiaohu; [e-mail]
> >> >>> Subject: Re: About the WG adoption of
> >> >>> draft-xu-l3vpn-virtual-subnet-fib-reduction-00
> >> >>>
> >> >>> Real loopbacks. E.g. A loopback /32 or /128 configured in the VRF
> >> >>>
> >> >>> On 30/07/14 10:52, "Xuxiaohu" <[e-mail]> wrote:
> >> >>>
> >> >>> >Hi Wim,
> >> >>> >
> >> >>> >Did you mean PE's loopback addresses by "real loopbacks"?
> >> >>> >
> >> >>> >Best regards,
> >> >>> >Xiaohu
> >> >>> >
> >> >>> >> -----Original Message-----
> >> >>> >> From: Henderickx, Wim (Wim)
> >> >>> >> [mailto:[e-mail]]
> >> >>> >> Sent: Wednesday, July 30, 2014 4:31 PM
> >> >>> >> To: Xuxiaohu; [e-mail]
> >> >>> >> Subject: Re: About the WG adoption of
> >> >>> >> draft-xu-l3vpn-virtual-subnet-fib-reduction-00
> >> >>> >>
> >> >>> >> What I would like to see is a way to identify the host routes
> >> >>> >>since there are 2
> >> >>> >> levels: real loopbacks that need to be installed by default
> >> >>> >>and real host routes  that can be installed on demand. It would
> >> >>> >>be good to show how the control  plane could distinguish them
> >> >>> >>using communities or the likes.
> >> >>> >>
> >> >>> >> On 30/07/14 08:54, "Xuxiaohu" <[e-mail]> wrote:
> >> >>> >>
> >> >>> >> >Hi all,
> >> >>> >> >
> >> >>> >> >Virtual Subnet
> >> >>> >> >(http://tools.ietf.org/html/draft-ietf-l3vpn-virtual-subnet)
> >> >>> >> >is intended for building L3 network virtualization overlays
> >> >>> >> >within and/or across data centers. Since a subnet is extended
> >> >>> >> >across multiple PE routers, CE host routes need to be
> >> >>> >> >exchanged among PE routers. As a result, the forwarding table
> >> >>> >> >size of PE routers (e.g., some old ToR
> >> >>> >> >switches) may become a big concern in large-scale data center
> >> >>> >> >environments. In fact, some folks had already expressed their
> >> >>> >> >concerns about this potential FIB scaling issue during the WG
> >> >>> >> >adoption poll of
> >> >>> >>the Virtual
> >> >>> >> Subnet draft.
> >> >>> >> >
> >> >>> >> >As CE host routes may still need to be maintained on the
> >> >>> >> >control plane of PE routers in some cases (e.g.. MVPN
> >> >>> >> >scenario), this draft
> >> >>> >> >(http://tools.ietf.org/html/draft-xu-l3vpn-virtual-subnet-fib
> >> >>> >> >-re
> >> >>> >> >d
> >> >>> >> >uct
> >> >>> >> >ion
> >> >>> >> >-00
> >> >>> >> >) proposes a very simple mechanism for reducing the FIB size
> >> >>> >> >of PE routers without any change to the RIB and even the
> >> >>> >> >routing
> >> >>>table.
> >> >>> >> >
> >> >>> >> >During the L3VPN WG session at Toronto, many people had
> >> >>> >> >expressed their supports for the WG adoption of this work
> >> >>> >> >(Thanks a lot for your supports). However, there are still a
> >> >>> >> >few people who are not in favor of the WG adoption. According
> >> >>> >> >to WG
> >> co-chairs'
> >> >>> >> >suggestion, I would like to request those opposers to explain
> >> >>> >> >their reasons so that we could further improve the draft if
> >> >>>possible.
> >> >>> >> >
> >> >>> >> >Best regards,
> >> >>> >> >Xiaohu (on behalf of all co-authors)
> >> >>> >> >
> >> >>> >
> >> >>
> >> >
> >