[j-nsp] Summarize Global Table

[Brad Fleming]

On Oct 27, 2011, at 3:38 PM, Tima Maryin wrote:
> On 25.10.2011 20:21, Brad Fleming wrote:
>> Are there any tricks to auto-summarize the contents of a RIB where the tributary routes are not originated locally?
>> 
>> Example:
>> Input routes:
>> prefix: 1.0.0.0/16, next-hop: 5.5.5.5
>> prefix: 1.0.1.0/16, next-hop: 5.5.5.5
>> prefix: 1.0.2.0/16, next-hop: 4.4.4.4
>> prefix: 1.0.3.0/16, next-hop: 5.5.5.5
>> 
>> Consolidated, Installed routes:
>> prefix: 1.0.0.0/14, next-hop: 5.5.5.5
>> prefix: 1.0.2.0/16, next-hop: 4.4.4.4
>> 
>> Basically a way to consolidate total number of prefixes entering the FIB.
>> 
>> If such a thing existed we could feed non-Juniper, TCAM-based routers a smaller table but still maintain the advantages of best path, hot potato routing.
> 
> 
> If you have got some peers/uplinks which are ISPs with full table there will eventually  be scenarios when you will be forced to hack some of you aggregates with specifics again and again to avoid blackholing. Since customers of those ISPs tends to use specifics to manipulate inbound traffic.
> 
> 
> If you're not ISP does 0/0 looks like an option? :)

We're an ISP; just a charitable, not-for-profit one with budget crunch issues right now. :D

I think we'll end up doing the aggregation approach and sacrificing the ability to offer BGP services from our aging CAM-based boxes. Fortunately we still have a reasonable amount of CAM; I'm just thinking what we can do before the 2015-2017 timeframe when the table growth will start to become an actual problem.

I do very much appreciate all the discussion, links, etc in this thread; I've learned of multiple new draft RFCs and some new ideas on approaching the issue. Thanks!