Baldur Norddahl wrote on 5/18/2019 3:57 AM:
...
One router knows about 2 paths, the other about 4 paths. Why? Because
BGP only advertises the route that is in use. Everyone here of course
knows this, I am just pointing it out because culling information
before allowing it to be redistributed within your network is what BGP
is already doing anyway. It is possible to remove some of that
information from the local FIB too without losing anything at all.
Using a default also gives you a dramatically shorter convergence time
if one of the transits goes down. Having 800k routes can be harmful to
your network even with equipment that can handle it. Yes I am aware
that I am not doing what I am preaching here, but I am considering it :-).
Thanks for the clarification. Yes, you are correct that each router will
have its own unique view. By full view I meant that a router has at
least one route for every prefix advertised into the DFZ. One should
also expect that each transit provider will provide a slight variation
in the routes provided via its "full BGP feed" because each transit
provider has its own unique view and may include routes in its feeds
that are not advertised into the DFZ.
Appreciate the discourse my friend,
--B
