Re: [Isis-wg] Comments on draft-xu-isis-flooding-reduction-in-msdc-00

[Hannes Gredler <[e-mail]>]

+1

i'd like to add to erik's observations that mesh-group support is
available in contemporary router software since 15+ years

/hannes

On 4/25/17 12:26, Erik Auerswald wrote:
> Hi Xiaohu,
> 
> please see my response inline (content not relevant to this
> response removed).
> 
> On Tue, Apr 25, 2017 at 08:46:06AM +0000, Xuxiaohu wrote:
>>> -----邮件原件-----
>>> 发件人: Erik Auerswald [mailto:[e-mail]]
>>> This idea can be realized using existing implementations, with additional
>>> possible optimizations via IS-IS extensions. In fact I built a lab today to play with
>>> the idea, using a couple of switches, one of which was used as controller, and
>>> the others as fabric switches.
>>
>> It would be great if you could share more information about your experiment:)
> 
> Nothing big, I just took four Extreme Networks X460[-G2] switches from
> the company lab, connected three switches in a row to build the "fabric"
> (you could think of the middle one as "spine" and the two at the ends
> as "leafs"), and then connected the fourth switch to all three "fabric"
> switches to act as "controller". I then configured IS-IS on the switches,
> configured a high metric on the links to/from the "controller" switch,
> and used the "meshBlocked" attribute from RFC 2973 to restrict flooding
> inside the "fabric." To do this I configured "meshBlocked" on all links
> between "fabric" switches.
> 
> Show outputs for transmitted LSPs showed flooding reduction (e.g. when
> adding a new loopback interface on a "leaf" switch), with full IP
> connectivity over the fabric. The "management" links to the "controller"
> were not used for "leaf" to "leaf" traffic due to the higher metric.
> 
>>> RFC 2973, IS-IS Mesh Groups, can be used to prevent flooding on the data path
>>> links.
>>
>> Could you explain more about how to apply the ISIS mesh group in the CLOS topology?
> 
> Please see above. RFC 2973 describes a method to configure individual links
> to inhibit flooding of LSPs using the "meshBlocked" attribute.
> 
> Thanks,
> Erik
>