CEF is not the only mechanism to implement distributed forwarding (within or without Cisco for that matter), and to say that distributed forwarding is faulty because of software complexities of one manufacturer, whose code base is built upon on a monolithic core (to use operating system would lower what it means to actually be a operating system) is to generalize all failures to a distributed architecture where the fault does not _always_ lie.
CEF and dCEF periodically break on Cisco. They break in the most interesting ways - the debugging indicates that the packets are going one way when they in reality are going the other way. Without CEF or dCEF Cisco's are useless for the amount of traffic that I am interested in. Juniper is very interesting. The only problem is a gazillion strange things that it tries doing. Juniper's BGP has very intereting bugs in confederations which I have discovered on the day #1 of putting one of them into production. That bug is still not fixed. Since confederations are very widely used, and no one else found this bug, and yet we have hit it nearly immediately, there is some sort of logical problem here. If something as simple as AS_PATH prepending in confederations does not work, I have some big reservations about things that are much more complex than that. Nortel has some exellent hardware that they have inherited from Bay Networks. Unfortunately, they still have not written the software to take any advantage of it, nor they developed it to the level where it can actually complete with the new offerings from the other vendors. Thanks, Alex
While a central architecture is simple, it has been shown within and beyond the industry that it does not scale.
David
-----Original Message----- From: alex@yuriev.com [mailto:alex@yuriev.com] Sent: Wednesday, April 11, 2001 1:41 PM To: nanog@merit.edu Subject: RE: gigabit router (was Re: Getting a "portable" /19 or /20)
Vendors have known how to solve this problem for many years. Failure to do so is a poor implementation and has nothing to do with centralized forwarding being better/worse than distributed forwarding.
Yet another person who does not understand the KISS principle. I am sure in theory it all works great, though I am seeing way too many comments similiar to:
"The connectivity issues have been resolved. This appears to be the same CEF related issues we experienced Monday evening, and we have a case open with Cisco. As we get more information from Cisco, we will be passing it along."
Alex