Announce your largest aggregate, and announce more-specifics tagged no-export to those peers who agree to accept them?
Which is worse than announcing just the more specifics to 2 different transit providers in 2 different cities.
Worse for those two transit providers, not the rest of the world.
Why won't the rest of the world see extra hops and increased latency reaching my network (for the 50% of the time that the wrong transit provider is picked).
Upgrade the connectivity between your sites? Technically sound, economically stupid. You offering to pony up the $5K/mth for an OC3 so I can have a redundant link between Ottawa and Toronto?
You are choosing to save money by poluting the global routing table. There may not be anything wrong with that, but don't be surprised when you hit providers who don't want or need to listen to your more specifics.
Stop whining about it and fix your announcements.
The proposed "fix" is a big mess. My solution doesn't add to the global routing table since I'm renumbering out of a few /24's to the /20 I received from ARIN. I'm only de-aggregating to a /23, not /24. My solution provides optimal routing vs announcing the /20 globally. The proposed "fix" will waste bandwidth, increase latency, and far more problematic to implement; how many NOC monkeys do you know that will be able to grasp the purpose of the 2 BGP sessions (one of them ebgp-multihop) let alone fix it if something goes wrong? -Ralph