BGP Path Attribute Filtering, YES or NO?

[saku at ytti.fi (Saku Ytti)]

On Wed, 8 Jan 2020 at 14:46, <adamv0025 at netconsultings.com> wrote:

> Other  might be: â??These experimental work is of great value to the community and thereâ??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 itâ??s not the case its good that these flaws are being exposed and fixed.â??

This is my position. Unfortunately it's a pipe dream, as you only need
very few to think filtering is needed to ruin the utility.

Some specific examples

- don't clean up communities which don't belong to you (
- don't clean up TOS byte (I may want to communicate QoS over internet
between my islands)
- don't clean up BGP attributes (128 would have utility if it transit,
but due to old issues, it often does not)
- don't drop ICMP (ICMP TS would be high utility if not filtered)

I think we need specific good reason to mangle/filter and if you
cannot come up with one, don't do it. If you can come up with one,
consider if it's persistent or workaround to deal with specific active
defect.

-- 
  ++ytti