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

["Henderickx, Wim (Wim)" <[e-mail]>]

The question is than do we want to standardise this community?

On 31/07/14 09:24, "Xuxiaohu" <[e-mail]> wrote:

>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)
>> >> >>> >> >
>> >> >>> >
>> >> >>
>> >> >
>> >
>