Policy-based routing is evil? Discuss.

[jtk at cymru.com (John Kristoff)]

On Fri, 11 Oct 2013 18:27:00 +0100 (BST)
William Waites <wwaites at tardis.ed.ac.uk> wrote:

> I'm having a discussion with a small network in a part of the world
> where bandwidth is scarce and multiple DSL lines are often used for
> upstream links. The topic is policy-based routing, which is being
> described as "load balancing" where end-user traffic is assigned to a
> line according to source address.

BGP is nothing if not policy-based routing, but I think I see your
concern with an approach that essentially statically locks in a
particular set of paths to links.

Not knowing what if any routing is configured between the end points,
perhaps just point out there are alternative means to achieve load
balancing.  Perhaps using LOCAL_PREF for some set of ASNs over one path
or the other, or alternatively doing some sort of flow-based load
balancing might be sufficient.

John