Check the duplex mode of the access switch
The switches that run Cisco IOS Software default to auto-negotiation for speed and are set to on for the duplex. The switches can also set their duplex setting with the duplex interface subcommand, and their speed with—you guessed it—the speed interface subcommand. This is only applicable for 10/100/1000 Mbps (1000BASE-T) NICs only Assuming maximum capability of Catalyst switch, and NIC is 1000 Mbps, full-duplex. I would like to know what duplex (half or full) my network card has negotiated with a switch when they are both set to auto configuration in Windows.
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