Ryan Hamel wrote on 06/12/2024 17:32:
That said, I can argue that upstreams not filtering their customers
properly removes a safety guard, upstreams not implementing RPKI removes
a safety guard, not properly prepending communities on synthetic routes
to drop them on export again removes a safety guard. I can go on...
There's a fundamental difference.
Not filtering customers properly fails to implement a safety guard that
should have been implemented. Not implementing RPKI fails to implement
an additional safety guard. Not properly prepending communities fails to
implement an additional safety guard.
Rewriting the AS path removes a core descriptive component of NLRIs
inherent in the BGP protocol which is critical to implementing other
safety guards.
Including - as an example of only of the harmful effects of this
practice - the ability for the upstream to automatically drop all routes
which you just reflected back to it, having just rewritten the AS path
to remove their ASN and rewrite the NHIP, because bgp loop-free routing
requires this by default in the protocol.
When you drop core safety components, accidents are more likely to happen.
Where this statement falls short is, those are all regulated by building
codes, laws, etc. No laws exist dictating how BGP, routing protocols in
general, and topologies must be implemented, nor what safety guidelines
must be adhered to.
The normal progression of many technologies ends in regulation. We
already have regulation which covers bgp inter-domain routing security
in the EU, and I'd be surprised if it wasn't going to happen in other
jurisdictions in due course.
In the US, warning shots have already been fired by the white house:
https://www.whitehouse.gov/wp-content/uploads/2024/09/Roadmap-to-Enhancing-Internet-Routing-Security.pdf
This style of document should be taken as notification that interdomain
routing security is fresh on the table of regulatory bodies in the US.
Nick
