Ralph, I think you're missing the point a bit. Don't expecy to use resources on other people's networks and routers to do your own traffic engineering unless you pay them for it. You must buy transit from the same ISP in each city, and then you can do your traffic engineering using their resources (i.e. send longer prefixes to them that are no-export). In essence you are using that transit ISP as *your* backbone. You could buy transit from teh same two providers in each city as has been suggested as well. If you don't want to do this then you must buy a private link between the cities and run your own backbone so that you can distribute the traffic inside your own AS. Learn how to use AS PATH PREPEND if you purchase equal sized pipes from unequal sized upstreams (i.e. BIG_GLOBAL_ISP and a regional ISP). If you don't like this then buy an AS for each city and run them as their own network as Joe suggested you could do. I don't like this solution as it does not really conserve routing annoucmenents, as you'll still be pushing out multiple longer prefixes (one /23 for each city), which will still be filtered by Verio and others, and you are eating up AS numbers which are scarce. I suppose if you could justify a /19 to /21 in each city this would be less of a problem. Those are your options ... essentially you need to A. Rent a backbone or B. Build a backbone On Sat, 27 Jul 2002, Ralph Doncaster wrote:
If you want to run seperate networks, run separate networks. Different ASes, the whole 9 yards; perhaps a re-reading of rfc1930 is in order?
That brings us back to the discussion of PI space. If de-aggregating my /20 didn't work, then I'd either inefficiently use IP space in order to qualify for 2 /20's, or buy a defunct ISP or 2 to get a bunch of /24's in the 192-223 space.
Are you suggesting that either of those (which don't violate any RFCs) options are better than de-aggregating my /20?
-Ralph
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