Actually, most of the RBOC/ILEC's use completely seperate AS's. "FCC Regulation" being a legitimate reason to request a whole bushel of AS's from ARIN. Try doing an ARIN whois on bellsouth, and you get... Bellsouth.Net (AS7891) BELLSOUTH-NET-BLK2 7891 - 7894 Bellsouth.Net (AS8060) BELLSOUTH-NET-BLK3 8060 - 8063 BellSouth.net Inc. (AS6380) BELLSOUTH-NET-BLK 6380 - 6389 - Dan On Wed, 13 Nov 2002, Scott Granados wrote:
Aren't some reasons for using disconnected as's regulatory based ie the bells etc?
On Wed, 13 Nov 2002 alex@yuriev.com wrote:
inherently wrong with using a single AS in multiple locations, and advertising discrete blocks of address space in each one. The best reason to do this is for a network that you eventually plan to merge - it eliminates issues of having to make major BGP configuration changes.
Nothing inherently wrong with it if you're paying for transit, but good luck getting peering in multiple locations without presenting consistent views.
No problem at all. Use a tunnel.
Going back to the original question:
(A) Is there a reason have disconnected ASs? Sure. Does it make more sense than using multiple AS numbers? No.
(B) Is there a reason to deaggregate? Absolutely. The biggest being rather bad internal allocations practiced by networks.
Alex
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