On Nov 21, 2009, at 4:29 AM, William Herrin wrote:
As I understand it, that's a feature, not a bug.
Any "feature" that can result in a long-lived forwarding loop seems like a non-starter to me. It would be interesting to hear from network operators who *don't* think long-lived forwarding loops are a problem. What's more, the bug I found should be easy to fix with little or no reduction in aggregation efficiency, so I don't see much justification for viewing it as a "feature".
It's present in both level 3 and level 4.
I don't think the bug I pointed out is in level 3 since it depends on aggregating across different next hops. Level 3 doesn't do this. If you see a potential for forwarding loops in level 3, an example would be helpful.
--John