Networks ignoring prepends?

Wed Jan 24 09:20:48 UTC 2024

On Wed, Jan 24, 2024 at 12:55 AM Owen DeLong <owen at delong.com> wrote:
> BGP is more of a PDVP (Policy Distance Vector Protocol).

Hi Owen,

That's a distinction without a difference. All but the most
rudimentary implementation of a distance-vector protocol supports
policy definition and enforcement. BGP has more policy knobs than
most, but at its heart it's still a distance-vector protocol and until
pushed off its default settings its first differentiator for distance
is the length of the AS path.

Only link-state protocols tend to lack policy knobs since all nodes
must agree about the correct full path, not just the next closest hop.

When you twist a policy knob to move BGP off its defaults, you take
responsibility for making a better routing choice. And for correcting
that choice if it should prove faulty. What I've seen here in this
thread is a bunch of folks abdicating that responsibility. That's not
unexpected, but it is disappointing.

Regards,
Bill Herrin

-- 
William Herrin
bill at herrin.us
https://bill.herrin.us/