nanog mailing list archives
Re: Spanning tree melt down ?
From: Stephen Stuart <stuart () tech org>
Date: Sat, 30 Nov 2002 19:10:29 -0800
I suspect we will learn more about what happened to Beth Israel Deaconess Hospital's network than we've ever heard publically about any of Worldcom's network problems. Dr. John Halamka has already publically stated he intends to tell other hospitals what happened and how they can avoid the same problem.
Hopefully it will be something along the lines of "complex layer 2 networks are fickle, and have vastly fewer mechanisms to implement policy than are available at layer 3; networks that serve different departments within the same organization are just as worthy of layer-3 policy boundaries as separate enterprises that have a need to keep their networks distinct." Sometimes the router or firewall that protects you from another department is just as valuable as the one that protects you from "the outside." Those of us who have been in the Ethernet-based exchange point business are well-aware of the dangers of building complex layer 2 topologies, especially when a portion of the customer base adds to the L2 fabric by fronting their router with an aggregation switch that is just as likely as not to be connected to another customer's aggregation switch without the first customer's knowledge ("we thought they provisioned a router port on their side, really"). Everyone claims to - and to be honest, many do - operate their L2 equipment correctly, but (funny thing) problems still occur. Administrative boundaries, and well-thought-out means of implementing those boundaries at places where networks touch, are important. Stephen
Current thread:
- Re: Spanning tree melt down ?, (continued)
- Re: Spanning tree melt down ? Stephen Sprunk (Nov 29)
- Re: Spanning tree melt down ? Daniel Golding (Nov 29)
- Re: Spanning tree melt down ? David Lesher (Nov 29)
- Re: Spanning tree melt down ? Daniel Golding (Nov 29)
- Re: Spanning tree melt down ? Rafi Sadowsky (Nov 29)
- Re: Spanning tree melt down ? Daniel Golding (Nov 29)
- Re: Spanning tree melt down ? Jim Segrave (Nov 30)
- Re: Spanning tree melt down ? Rafi Sadowsky (Nov 30)
- Re: Spanning tree melt down ? Stephen Sprunk (Nov 30)
- Re: Spanning tree melt down ? Sean Donelan (Nov 30)
- Re: Spanning tree melt down ? Stephen Stuart (Nov 30)
- Re: Spanning tree melt down ? David Lesher (Nov 29)
- Re: Spanning tree melt down ? David Diaz (Nov 29)
- Re: Spanning tree melt down ? alex (Nov 27)
- Re: Spanning tree melt down ? Scott Granados (Nov 27)
- Re: Spanning tree melt down ? Garrett Allen (Nov 28)
- Re: Spanning tree melt down ? Simon Lyall (Nov 28)
- Re: Spanning tree melt down ? Stephen J. Wilcox (Nov 28)
- Re: Spanning tree melt down ? Robert A. Hayden (Nov 28)