Would like to gather current views of a wider community on BGP Path Attribute Filtering (discarding selected attributes in particular, not treat as withdraw) as an addition to the long list of standard conditioning tools like max as-path length limit, limiting number of communities all the way to running iBGP infrastructure to carry Internet prefixes separate to the one carrying customers’ L3/L2VPN prefixes.

And I appreciate the topic is somewhat contentious and there’s no simple yes or no answer either.

My view is that in a stub AS there should be no harm in discarding unused BGP path attributes,

On transit AS-es I’d expect two opposing views:

One might be: “I have a business to run and don’t care about some university experiments, so unless any of my customers specifically asks for some attribute I’ll drop all reserved, unassigned and deprecated ones and might even drop some not widely used ones just to be on the well-trodden bug free path”

Other  might be: “These experimental work is of great value to the community and there’s a process now to announce and manage these experiments, what about net neutrality, and besides modern BGP implementations should handle well formatted attributes and if it’s not the case its good that these flaws are being exposed and fixed.”

Please let me know your thoughts.

adam