Open letter to Level3 concerning the global routing issues on June 12th

Sat Jun 13 10:34:35 UTC 2015

On 12/Jun/15 19:12, Job Snijders wrote:
>  
>
> The simplest protection mechanism of all: maximum prefix limits. If you
> turn up a peer or customer, confirm with them how many routes you should
> expect, add 15% and configure that. 

For peering and customers, we set a default prefix limit value for IPv4
and IPv6. We only change this if the peer/customer informs us that they
will announce a lot more than what we've configured. We add some % to
cover for "sudden" growth, but not too much to impact the network.

For customers, we add prefix lists and AS_PATH filters as mandatory.

I'm sure others do the same. It would be good if we all did.

I know the largest transit providers tend to be more relaxed for various
reasons. Some rely on filters generated by IRR entries, others don't.

A lot more work is needed, indeed. It's not 2008 anymore...

Mark.