[c-nsp] /18 and multihomed BGP

[Heath Jones]

I mentioned that also...

On 13 August 2010 17:51, Adam Armstrong <lists at memetic.org> wrote:

> On 13/08/2010 17:00, Heath Jones wrote:
>
>> Robert's response pretty much covers it all really.
>> If those 2 ISP's are advertising /24's out to the wider internet, your
>> screwed. Traffic will never come down via this new ISP.
>> The way to solve it, is to advertise the /24's as you already are, but
>> get those 2 ISP's to summarize into a /18 before they export, or you
>>
>
> That's quite a confusing explanation. You don't get the ISP to "summrize"
> anything. You announce both the /18 and the /24s. The /24s should be
> advertised either with no-export or with other communities to suppress their
> advertisement outside of the ISPs (or region) involved.
>
> adam.
>
>
>