Hi Ca,

> Noction is sold to ISPs, aka transit AS, afaik  

Interesting. 

My impression always was by talking to Noction some time back that mainly what they do is a flavor of performance routing.  But this is not about Noction IMHO. 

If I am a non transit ASN with N upstream ISPs I want to exit not in a hot potato style ... if I care about my services I want to exit the best performing way to reach back customers. That's btw what Cisco PFR does or Google's Espresso or Facebook Edge Fabric etc ... 

And you have few vendors offering this as well as bunch of home grown tools attempting to do the same. Go and mandate that all of them will do NO-EXPORT if they insert any routes ... And we will see more and more of those type of tools coming. 

Sure we have implementations with obligatory policy on eBGP - cool. And yes we have match "ANY" too. 

So if your feedback is that to limit the iBGP routes to go out over eBGP this is all sufficient and we do not need a bit more protection there then case solved. 

Cheers,

R.

On Sun, Aug 2, 2020 at 4:42 PM Ca By <cb.list6@gmail.com> wrote:

On Sun, Aug 2, 2020 at 4:34 AM Robert Raszuk <robert@raszuk.net> wrote:

All,

Watching this thread with interest got an idea - let me run it by this list before taking it any further (ie. to IETF). 

How about we learn from this and try to make BGP just a little bit safer ? 

Idea: 

In all stub (non transit) ASNs we modify BGP spec and disable automatic iBGP to eBGP advertisement ? 

Why do you believe a stub AS was involved or that would have changed this situation?

The whole point of Noction is for a bad isp to fake more specific routes to downstream customers.  Noction is sold to ISPs, aka transit AS, afaik

Implementation: 

Vendors to allow to define as part of global bgp configuration if given ASN is transit or not. The default is to be discussed - no bias. 

Oh. A configuration knob. Noction had knobs, the world runs of 5 year old software with default configs. 

Benefit: 

Without any issues anyone playing any tools in his network will be able to just issue one cli

Thanks for no pretending we configure our networks with yang model apis

and be protected from accidentally hurting others. Yet naturally he will still be able to advertise his neworks just as today except by explicit policy in any shape and form we would find proper (example: "redistribute iBGP to eBGP policy-X").

XR rolls this way today, thanks Cisco. But the “any” keyword exists, so yolo. 

We could even discuss if this should be perhaps part of BGP OPEN or BGP capabilities too such that two sides of eBGP session must agree with each other before bringing eBGP up. 

Comments, questions, flames - all welcome :)  

Cheers,

Robert.

 

PS. Such a definition sure can and likely will be misused (especially if we would just settle on only a single side setting it - but that will not cause any more harm as not having it at all. 

Moreover I can already see few other good options which BGP implementation or BGP spec can be augmented with once we know we are stub or for that matter once it knows it is transit ....