These standards do drag on don't they. I'd suggest that customers need to come along and crack the whip a bit to help keep us grounded and moving.good excuse to travel somewhere warm ;) On the 802.1aq comment, we are doing MIBs/cleanup now so it should be out by end of this year so its probably time for an 802.1aq tutorial at NANOG. Peter Ashwood-Smith. _____ From: James Hess <mysidia () gmail com> Date: Fri, 26 Mar 2010 23:13:11 -0500 _____ On Fri, Mar 26, 2010 at 9:29 PM, Chuck Anderson <cra () wpi edu> wrote: So basically, the problem is the core switches implement a proprietary loop-prevention protocol that sends "beacon" frames out every 500ms, and if a certain number of these special frames come back (exceeds --> loop first, but I'm beginning to think that this protocol is crap and I should just disable it and let the core ride out the loop in the Ah, nasty.. it seems like you definitely should want to keep the beacon frames from getting injected then. Taking down core links ought to be harder than 1 user emitting a few frames. A malicious user, or a naive user with a malicious trojan on their computer could try to send fake beacons, to cause trouble. I for one might start thinking if the beacons can be sunk from end user ports by brute force, using a Layer 2 ACL. I wonder if RFC 5556, IETF TRILL specs, or 802.1aq/802.1Qbb / Datacenter Ethernet / Bridging standards and more robust standards-based loop avoidance standards will ever get finalized, considering they have been drafts for over 5 years, it seems like the standardization is very sluggish. A new protocol is probably the right solution, but it might not be ready until 2015 at this rate. Anyone know if Auto MDI/MDI-X is inherent or required in 1000Base-T? It would be nice if I could shut it off. Auto MDI/MDI-X is an optional feature in the 1000BaseT standard. Automatic negotiation of speeds and duplex, is mandatory due to 802.3ab, but not auto-crossover You can get that here http://standards.ieee.org/getieee802/802.3.html Clause 40.4.4 in IEEE 802.3-2008 -- Section Three states the following: "40.4.4 Automatic MDI/MDI-X Configuration Automatic MDI/MDI-X Configuration is intended to eliminate the need for crossover cables between simi lar devices. Implementation of an automatic MDI/MDI-X configuration is optional for 1000BASE-T devices. If an automatic configuration method is used, it shall comply with the following specifications. The assignment of pin-outs for a 1000BASE-T crossover function cable is shown in Table40-12 in 40.8. "