Cisco Catalyst 9300 Series Switches: Настройка Auto-MDIX (Руководство пользователя)

Information About Configuring Auto-MDIX

Configuring Auto-MDIX Prerequisites for Auto-MDIX, on page 1 Restrictions for Auto-MDIX, on page 1 Information About Configuring Auto-MDIX, on page 1 How to Configure Auto-MDIX, on page 2 Example for Configuring Auto-MDIX, on page 3 Auto-MDIX and Operational State, on page 3 Additional References for Auto-MDIX, on page 4 Feature History for Auto-MDIX, on page 4 Prerequisites for Auto-MDIX To configure Layer 2 parameters, if the interface is in Layer 3 mode, you must enter the switchport interface configuration command without any parameters to put the interface into Layer 2 mode.

This shuts down the interface and then re-enables it, which might generate messages on the device to which the interface is connected. When you put an interface that is in Layer 3 mode into Layer 2 mode, the previous configuration information related to the affected interface might be lost, and the interface is returned to its default configuration. Automatic medium-dependent interface crossover (auto-MDIX) is enabled by default. Auto-MDIX is supported on all 10/100/1000-Mb/s and on 10/100/1000BASE-TX small form-factor pluggable (SFP)-module interfaces. It is not supported on any other SFP, SFP+, or QSFP module interface.

Restrictions for Auto-MDIX The device might not support a pre-standard powered device—such as Cisco IP phones and access points that do not fully support IEEE 802.3af—if that powered device is connected to the device through a crossover cable. This is regardless of whether auto-MIDX is enabled on the switch port. Information About Configuring Auto-MDIX The following sections provide information about Auto-MDIX. Configuring Auto-MDIX 1

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Configuring Auto-MDIX on an Interface

Auto-MDIX on an Interface When automatic medium-dependent interface crossover (auto-MDIX) is enabled on an interface, the interface automatically detects the required cable connection type (straight through or crossover) and configures the connection appropriately. When connecting devices without the auto-MDIX feature, you must use straight-through cables to connect to devices such as servers, workstations, or routers and crossover cables to connect to other devices or repeaters. With auto-MDIX enabled, you can use either type of cable to connect to other devices, and the interface automatically corrects for any incorrect cabling.

For more information about cabling requirements, see the hardware installation guide. Auto-MDIX is enabled by default. Note This table shows the link states that result from auto-MDIX settings and correct and incorrect cabling. Table 1: Link Conditions and Auto-MDIX Settings How to Configure Auto-MDIX The following sections provide configurational information about Auto-MDIX. Configuring Auto-MDIX on an Interface Auto MDIX is turned on by default. To disable Auto MDIX on a port, use the no mdix auto command under the interface configuration mode. To put it back to default, use the mdix auto command in the interface configuration mode. The following steps show how to enable the Auto MDIX.

Procedure Configuring Auto-MDIX Auto-MDIX on an Interface LocalSideAuto-MDIX RemoteSideAuto-MDIX WithCorrectCabling WithIncorrectCabling On On Link up Link up On Off Link up Link up Off On Link up Link up Off Off Link up Link down Command or Action Purpose Step 1 enable Example: Device> enable Enables privileged EXEC mode. Enter your password, if prompted. Step 2 configure terminal Example: Device# configure terminal Enters global configuration mode Configuring Auto-MDIX 2

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Auto-MDIX and Operational State

Example for Configuring Auto-MDIX This example shows how to enable auto-MDIX on a port: Device# configure terminal Device(config)# interface gigabitethernet1/0/1 Device(config-if)# mdix auto Device(config-if)# end Auto-MDIX and Operational State Table 2: Auto-MDIX and Operational State Configuring Auto-MDIX Example for Configuring Auto-MDIX Command or Action Purpose Step 3 interface interface-id Example: Device(config)# interface gigabitethernet1/0/1 Specifies the physical interface to be configured, and enter interface configuration mode. Step 4 mdix auto Example: Device(config-if)# mdix auto Enables the Auto MDIX feature. Step 5 end Example:

Device(config-if)# end Returns to privileged EXEC mode. Step 6 copy running-config startup-config Example: Device# copy running-config startup-config (Optional) Saves your entries in the configuration file. Auto-MDIX Setting and Operational State on an Interface Description Auto-MDIX on (operational: on) Auto-MDIX is enabled and is fully functioning. Auto-MDIX on (operational: off) Auto-MDIX is enabled on this interface but it is not functioning. To allow auto-MDIX feature to function properly, you must also set the interface speed to be autonegotiated. Auto-MDIX off Auto-MDIX has been disabled with the no mdix auto command. Configuring Auto-MDIX 3

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Feature History for Auto-MDIX

Additional References for Auto-MDIX Related Documentation Feature History for Auto-MDIX This table provides release and related information for features explained in this module. These features are available on all releases subsequent to the one they were introduced in, unless noted otherwise. Use Cisco Feature Navigator to find information about platform and software image support. To access Cisco Feature Navigator, go to Cisco Feature Navigator . Configuring Auto-MDIX Additional References for Auto-MDIX Related Topic Document Title For complete syntax and usage information for the commands used in this chapter.

Command Reference (Catalyst 9300 Series Switches) For information about the power supplies. Cisco Catalyst 9300 Series Switches Hardware Installation Guide Release Feature Feature Information Cisco IOS XE Everest 16.5.1a Auto-MDIX on an Interface An automatic medium-dependent interface crossover (Auto-MDIX) enabled interface detects the required cable connection type (straight through or crossover) and configures the connection appropriately. Configuring Auto-MDIX 4

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