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Re: Transit LAN vs. Individual LANs
On Feb 25, 2006, at 9:23 PM, Owen DeLong wrote:
Unfortunately it seems that not all devices actually implement MDI/MDI-X--On February 25, 2006 8:09:22 PM +0000 "Christopher L. Morrow" <[email protected]> wrote:On Sat, 25 Feb 2006, Neil J. McRae wrote:So, perhaps I missed the earlier explanation, but why use switchedAn argument could be made for individual VLANs to keep things like b- cast storms isolated. But I think the additional complexity will cause more problems than it will solve.Vlans will not stop all typres of broadcast storm.
IEE Std 802.3ab-1999, 40.4.4 (Page 93) says:
"Implementation of an automatic MDI/MDI-X configuration is optional for 1000BASE-T devices".
IEE Std 802.3ab-1999, 40.8,2 (Page 93) says:
"Although the automatic MDI-<DI-X configuration (see 40.4.4) is not required for successful operation of 1000BASE-T, is is a functional requirement that a cross-over function be implemented in every link segment to support the operation of Auto-Negotiation"
Now, seeing as Auto-Negotiation is required, it implies that automatic MDI/MDI-X is also required -- however, certain vendors seem to ignore this....
Thus, you can use any eia-568[ab] cable, straight or crossed between them. (Note, USOC cables still won't work, it has to be 568a or 568b pairing) Owen -- If it wasn't crypto-signed, it probably didn't come from me.