CloudFlare IPv6 BGP announcements - WTF guys?

Bernhard Schmidt berni at
Mon Jul 16 22:27:37 CEST 2012

On 16.07.2012 21:15, Daniel Roesen wrote:

>> If your modus operandi is to pollute the routing tables, you deserve all the
>> unreachability you get.
> Wether you see /32 PA more-specifics from all the CDN nodes, or PI /48s
> doesn't make a difference at all, technically.

It does in a way. With multiple allocated prefixes (be it /32 or /48, I 
don't care) you can be reasonably certain it has been "designed" this 
way for your non-interconnected sites. With dozens 
less-than-allocation-size prefixes there is no way to programatically 
seperate you from the next hillbilly-ISP that never heard of communities 
or proper aggregation and just announces their whole iBGP into the world.

Sure, you can put exceptions for Akamai and Cloudflare in your filters. 
And then the next CDN-of-the-day, and then ...

I have absolutely nothing against proper and reasonable use of BGP, be 
it more-specific or otherwise, but I don't want the next iBGP leak 
hitting my routers. So I was filtering on /36 for PA space until now, 
hoping for a consensus in the community. Since Akamai still does not 
have that /32 in the air again I have to assume it is intentional and 
the battle for strict filtering is essentially lost.


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