Re: Verio Decides what parts of the internet to drop
Dr. Li wrote:
Date: Fri, 03 Dec 1999 23:35:18 -0800 From: Tony Li <tony1@home.net> Subject: Re: Verio Decides what parts of the internet to drop
I'll also note that this would also decrease the pressure on the address space. No need to go get a /19 if I can get my /23 globally advertised. : : The correlation with route flap should be re-examined. I suspect that this is no longer a driving force and is more than adequately compensated for by having flap damping parameters that scale geometrically with the prefix length.
To state an obvious extension of these ideas: Without relief, space registrants are thus incented to (continue to) subvert the spirit of the allocation scheme in order to overcome its deficiencies. In doing so, a trend toward lower (shorter) "characteristic prefix length" is created by networks that would otherwise be suited by smaller allocations closer to their actual occupancy. Metastability in interdomain routing is currently maintained by an algorithm [1] that suppresses oscillations to an acceptable level, deferring treatment of another "interesting problem" [2,3]. If distinctions between highly aggregated networks and large, underoccupied ones are progressively obscured, strategies that inversely correlate prefix length with oscillatory period may be circumvented. Past experience [*] suggests that further detraction from the elusive "global routing stability" is more poignant and at greater issue to operators than the combined problems of address occupancy and table population. Indeed, it seems that a review of operational policy is in order. Regards, Andrew Bender Total Network Solutions, Inc. [1] C. Villamizar, R. Chandra, R. Govindan. RFC 2439. [2] K. Varadhan, R. Govindan, and D. Estrin. Persistent route oscillations in inter-domain routing. USC/Information Sciences Institute, 1996. [3] T. Griffin, G. Wilfong. An Analysis of BGP Convergence Properties. Computer Communication Review, October 1999. [*] http://www.techweb.com/wire/story/TWB19991202S0002
Based on past experiences, I would say that the big backbone providers shouldn't do any filtering at all. Then, the lower tiers can do all the filtering they want, and still rely on default routing to send the packets to the backbone. It may not be the prettiest way to route traffic, but this would allow smaller ISPs to filter if they cannot afford buying bigger equipment to hold all the routes. Since the tier-1 guys are the glue of the Internet, they should be required to take everyone routes. -- James Smith, CCNA Network/System Administrator DXSTORM.COM http://www.dxstorm.com/ DXSTORM Inc. 2140 Winston Park Drive, Suite 203 Oakville, ON, CA L6H 5V5 Tel: 905-829-3389 (email preferred) Fax: 905-829-5692 1-877-DXSTORM (1-877-397-8676) It's Unix or nothing! On Mon, 6 Dec 1999, Andrew Bender wrote:
Dr. Li wrote:
Date: Fri, 03 Dec 1999 23:35:18 -0800 From: Tony Li <tony1@home.net> Subject: Re: Verio Decides what parts of the internet to drop
I'll also note that this would also decrease the pressure on the address space. No need to go get a /19 if I can get my /23 globally advertised. : : The correlation with route flap should be re-examined. I suspect that this is no longer a driving force and is more than adequately compensated for by having flap damping parameters that scale geometrically with the prefix length.
To state an obvious extension of these ideas:
Without relief, space registrants are thus incented to (continue to) subvert the spirit of the allocation scheme in order to overcome its deficiencies. In doing so, a trend toward lower (shorter) "characteristic prefix length" is created by networks that would otherwise be suited by smaller allocations closer to their actual occupancy.
Metastability in interdomain routing is currently maintained by an algorithm [1] that suppresses oscillations to an acceptable level, deferring treatment of another "interesting problem" [2,3]. If distinctions between highly aggregated networks and large, underoccupied ones are progressively obscured, strategies that inversely correlate prefix length with oscillatory period may be circumvented.
Past experience [*] suggests that further detraction from the elusive "global routing stability" is more poignant and at greater issue to operators than the combined problems of address occupancy and table population.
Indeed, it seems that a review of operational policy is in order.
Regards, Andrew Bender Total Network Solutions, Inc.
[1] C. Villamizar, R. Chandra, R. Govindan. RFC 2439. [2] K. Varadhan, R. Govindan, and D. Estrin. Persistent route oscillations in inter-domain routing. USC/Information Sciences Institute, 1996. [3] T. Griffin, G. Wilfong. An Analysis of BGP Convergence Properties. Computer Communication Review, October 1999. [*] http://www.techweb.com/wire/story/TWB19991202S0002
participants (2)
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Andrew Bender -
James Smith