On Fri, Jun 05, 2020 at 10:20:00AM -0700, William Herrin wrote: > On Fri, Jun 5, 2020 at 9:49 AM Saku Ytti <[email protected]> wrote: > > The comparison isn't between full or default, the comparison is > > between static default or dynamic default. Of course with any default > > scenario there are more failure modes you cannot route around. But if > > you need default, you should not want to use dynamic default. > > It's a little more nuanced than that. You probably don't want to > accept a default from your transit but you may want to pin defaults > (or a set of broad routes as I did) to "representative" routes you do > accept from your transit. By "pin" I mean tell BGP that 0.0.0.0/0 is > reachable by some address inside a representative route you've picked > that is NOT the next hop. That way the default goes away if your > transit loses the representative route and the default pinned to one > of your other transits takes over.
I do the above using routes to *.root-servers.net to contribute to the aggregate 0/0.
