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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Cisco 4000 series switches
Please excuse the duplicate post (If there is one) Hello all, After being tasked to diagnose why a node is reporting a Half duplex connection I ran across an unusual observation. I've pretty much always assumed that what a switch reported as a status regarding the link of a node was the actual status of the line to be the case. However, when I checked the actual line state using a Fluke Net tool box I was surprised to discover a discrepancy. The scenario is this, the unit in question is a Cisco 4006 Catalyst. The port being connected to is set to Auto negotiate. Once the unit in question connects over a fairly poor RJ-45 connection using auto negotiate (no not beyond 100 meters, actually 280 feet) the switch reports: Port Name Status Vlan Level Duplex Speed Type ----- ------------------ ---------- ---------- ------ ------ ----- ------------ 3/2 connect 106 normal a-full a-100 10/100BaseTX However the line analyzer says duplex is half, but advertised full. When I set the node in question to Half Duplex, the switch reports half duplex as well. Port Name Status Vlan Level Duplex Speed Type ----- ------------------ ---------- ---------- ------ ------ ----- ------------ 3/2 connect 106 normal a-half a-100 10/100BaseTX Is this a common situation or just a mis-understanding of the column that makes up Duplex for the Cisco IOS? Or is it that The Cisco Switch truly is trying to do full duplex but the end node is only doing half. If so would/should I see line errors at some point under heavy load/traffic? And if not why would the line analyzer see the connection as half when the switch is reporting full? And btw, Firmware is at 5.5(11) Any thoughts appreciated. TIA -Joe
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