On Sat, 13 Jun 2015, Mark Tinka wrote:
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...
At my previous job (regional ISP with a decent amount of BGP-speaking downstream customers), we did prefix and AS-PATH filtering on all customer sessions. The only thing lacking at that time (1997-2004) was a decent way to automate changes - everything was pretty manual. That said, it kept issues caused by customers leaking routes back to us down to pretty much nil. jms