Re: [Int-area] Where to aggregate, where to drop

[Tony Li <[e-mail]>]

Hi Dino,


>> As always, it’s a trade-off.  In this case, do you want to optimize your routing resources or a small amount of bandwidth.  You can either carry more specifics or drop P.4 traffic.  IMHO, that’s an easy call.
> 
> Not at all clear that its a small amount of bandwidth.


Other than a DoS attack, why would it be significant?

>>>>> Another question is, if all more-specfics are not stored (due to major link failure), is the aggregate withdrawn from the routing system. That is, if you want less route flapping, you may just want to keep P advertised. That optimizes FIB add/delete entropy everywhere that wants to store P. I would rather have hardware routers drop packets fast, then to have route oscillation.
>>>> 
>>>> 
>>>> Yes, if ISP B isn’t getting all of the more specifics and continues to aggregate, it could attract traffic that it can’t deliver. Presumably this is a transient until it can get the more specifics.
>>> 
>>> So what is your conclusion? Is your draft saying to optimize traffic engineering or saving routing table space? Or simply documenting the tradeoffs?
>> 
>> 
>> I’m saying do both: aggregate at the right place and it’s a win-win.  But figuring out where to aggregate does require some thought.
> 
> Definitely agree.


So the draft is supposed to help people think about it. :)

Do you think it’s worth of WG adoption?

T