Catalyst 4500 Series Switch Software Configuration Guide, Release IOS XE 3.3.0SG and IOS 15.1(1)SG

Understanding the Ethernet Management Port

The Ethernet management port, also referred to as the Fa1 or fastethernet1 port , is a Layer 3 host port to which you can connect a PC. Use the Ethernet management port instead of the switch console port for network management. When managing a switch, connect the PC to the Ethernet management port on a Catalyst 4500 series switch. (Figure 7-1).

NoteWhen connecting a PC to the Ethernet management port, you must assign an IP address. When connecting a PC to the Ethernet management port, you must assign an IP address.

Figure 7-1 Connecting a Switch to a PC

By default, the Ethernet management port is enabled. The switch cannot route packets from the Ethernet management port to a network port, and from the network port to the Ethernet port. To obtain these, the Fa1 interface is automatically placed in a separate routing domain (or VRF domain), called mgmtVrf. (You observe the ip Vrf forwarding mgmtVrf line in the running configuration when you boot up.) For details, read the “Fa1 Interface and mgmtVrf” section.

Even though the Ethernet management port does not support routing, you might need to enable routing protocols on the port. As illustrated in Figure 7-2, you must enable routing protocols on the Ethernet management port when the PC is multiple hops away from the switch and the packets must pass through multiple Layer 3 devices to reach the PC.

Figure 7-2 Network with Routing Protocols Enabled

The specific implementation of Ethernet management port depends on the redundancy model you are applying.

Fa1 Interface and mgmtVrf

All features that use fa1 now need to be VRF-aware.

NoteYou cannot configure any other interface in the same routing domain and you cannot configure a different routing domain for the Fa1 interface. You cannot configure any other interface in the same routing domain and you cannot configure a different routing domain for the Fa1 interface.

On bootup the fa1 port assumes the following default configuration:

Because the management port is placed in mgmtVrf, you should be aware of the VRF aware commands required for the following tasks:

• Ping
• TraceRoute
• Telnet
• TFTP
• FTP
• SSH

NoteCommand usage specific to the mgmtVrf are mentioned below. The additional configuration that is necessary to make the feature work needs to be configured. Command usage specific to the mgmtVrf are mentioned below. The additional configuration that is necessary to make the feature work needs to be configured.

Ping

If you want to ping an IP address that is reachable through an fa1 port, enter the following command:

For example:

TraceRoute

Telnet

If you want to Telnet to a remote switch through the Fa1 port, enter the following command:

Following is an example illustrating how to use this command:

TFTP

If you want to use Fa1 port for TFTP operation, configure the Fa1 port as the source interface for TFTP as follows:

FTP

If you want to use an Fa1 port for an FTP operation, configure the Fa1 port as the source interface for FTP as follows:

SSH

If you want initiate SSH from your switch through the Fa1 port, enter the following command:

For example:

SSO Model

On a redundant chassis, management port behavior differs from that of a standard Ethernet port in that each supervisor engine possesses a management port, and only the port on the active supervisor engine is enabled. The management port on the standby supervisor engine is always disabled; it cannot switch any kind of traffic.

When a switchover occurs, the management port of the standby supervisor engine (now, active) is enabled and can be used to switch traffic, while the management port on the “old” active supervisor engine is disabled.

NoteThe Cisco IOS configuration for the management port is synchronized between the two supervisor engines. Under Cisco IOS, they possess the same IP address. To avoid address overlapping during a switchover on a redundant chassis, you should assign a different IP address on the management port from the one you assigned to the same port in the ROMMON configuration. The Cisco IOS configuration for the management port is synchronized between the two supervisor engines. Under Cisco IOS, they possess the same IP address. To avoid address overlapping during a switchover on a redundant chassis, you should assign a different IP address on the management port from the one you assigned to the same port in the ROMMON configuration.

ISSU Model

In SSO mode, the running configurations on the active and standby supervisor engines must match. You cannot enable the management port on a redundant chassis if one of the two supervisor engines is running an Cisco IOS image prior to Cisco IOS Release 12.2(50)SG (wherein a management port is not supported).

When you perform an ISSU upgrade or downgrade between Cisco IOS Release 12.2(50)SG and a software image prior to Cisco IOS Release 12.2(50)SG, we automatically disable the management port. The port configuration is restored when both software images running on the supervisor engines are at least Cisco IOS Release 12.2(50)SG. A warning message is also displayed.

Supported Features on the Ethernet Management Port

The Ethernet management port supports these features:

• Express setup
• Network Assistant
• Telnet with passwords
• TFTP
• Secure Shell (SSH)
• DHCP-based autoconfiguration
• SNMP (only the ENTITY-MIB and the IF-MIB)
• IP ping
• Interface features

– Speed—10 Mb/s, 100 Mb/s, 1000Mb/s, and autonegotiation

– Duplex mode—Full, half, and autonegotiation

– Loopback detection

• Cisco Discovery Protocol (CDP) (only on WS-C4900M and WS-C4948)
• IPv4 access control lists (ACLs)
• Routing protocols (only on WS-C4900M and WS-C4948)
• AAA

Configuring the Ethernet Management Port

To specify the Ethernet management port, enter fastethernet1.

To disable the port, use the shutdown interface configuration command. To enable the port, use the
no shutdown interface configuration command.

To determine the link status to the PC, you can monitor the LED for the Ethernet management port:

• The LED is green (on) when the link is active.
• The LED is off when the link is down.
• The LED is amber when there is a POST failure.

To display the link status, use the show interfaces fastethernet 1 privileged EXEC command.

Port Numbering TwinGig Convertors

When a TwinGig Convertor is enabled or disabled, the number and type of ports on the line card change dynamically. The terminology must reflect this behavior. In Cisco IOS, 10-Gigabit ports are named 10-Gigabit and 1-Gigabit ports are named Gigabit. Starting with Cisco IOS Release 12.2(40)SG, to avoid having two ports named 10-Gigabit1/1 and Gigabit1/1, the 10-Gigabit and 1-Gigabit port numbers are independent. For example, for a WS-X4606-10GE-E module with six X2 holes, the X2 ports are named 10-Gigabit slot-num/<1-6>, and the SFP ports are named Gigabit slot-num/<7-18>.

Figure 7-3 Faceplate for WS-X4606-10GE

In Cisco IOS, ports 1 through 18 always exist. This means that you can apply configurations on them and they display in the CLI output. However, only the X2 or the SFP ports can be active at any particular time. For example, if an X2 is plugged into the second hole, the X2 port 2 is active and SFP ports 9 and 10 are inactive. If a TwinGig Convertor is plugged into the second hole, the X2 port 2 is inactive, and the SFP ports 9 and 10 are active. The inactive ports are treated analogously to the inactive ports on Supervisor Engines IV and V-10GE, where at no time are all of the uplinks connected to the switching ASICs.

NoteWhen using both TwinGig and X2 transceivers on the WS-X4606-X2-E module, place ports 1-3 in one group and ports 4-6 in another. (The mode selected with the show hw-module module port-group command determines the behavior. See When using both TwinGig and X2 transceivers on the WS-X4606-X2-E module, place ports 1-3 in one group and ports 4-6 in another. (The mode selected with the show hw-module module port-group command determines the behavior. See “Selecting X2/TwinGig Convertor Mode”.) Mixing within a port group does not work. For example, you cannot have an X2 in port 1 and a TwinGig in port 2 and expect both of them to function.

Limitations on Using a TwinGig Convertor

Supervisor Engine 6-E, Supervisor Engine 6L-E, and Catalyst 4900M connect ports to the switching engine through a stub ASIC. This stub ASIC imposes some limitations on the ports: Gigabit and 10-Gigabit ports cannot be mixed on a single stub ASIC; they must either be all 10-Gigabit Ethernet (X2), or all Gigabit (TwinGig Converter and SFP). The faceplates of X2 modules show this stub port grouping, either with actual physical grouping with a box drawn around a grouping.

Selecting X2/TwinGig Convertor Mode

The default configuration mode is X2. If you plan to deploy 10-Gigabit Ethernet interfaces, you do not need to configure anything. However, if you want to deploy Gigabit interfaces (that is, use TwinGig Convertors), you must configure the associated port-group:

To determine how the X2 holes on a module are grouped, enter the show hw-module module m port-group p command.

Note Place a 10-Gigabit Ethernet port that accepts CVR-X2-SFP into 1-Gigabit mode instead of 10-Gigabit Ethernet mode.

If you configure a 10-Gigabit Ethernet port as 1-Gigabit port, an output similar to the following appears:

If the port is set to the default, 10-Gigabit Ethernet mode, an output similar to the following appears:

• To configure the modes of operation for each X2 port group in which you want to deploy Gigabit, enter the hw-module module m port-group p select gigabitethernet command. This configuration is preserved across power cycles and reloads.

To deploy Gigabit Ethernet interfaces using the TwinGig Convertor, perform this task:

This example shows how to select Gigabit Ethernet interfaces on a WS-X4606-10GE-E using the TwinGig Convertor:

Single Supervisor Mode

In single supervisor mode, WS-X45-SUP-7L-E supports the uplink configuration of at most either two 10-Gigabit or four 1-Gigabit ports ( Table 7-1 ).

SFP+ and SFP can be inserted in any order for lines 2 thru 4.

Redundant Supervisor Mode

In redundant supervisor mode, WS-X45-SUP-7L-E supports 1+1 (in 10-Gigabit mode) and 2+2 (in 1-Gigabit mode) ( Table 7-2 ).

Configuring Ethernet Interface Speed and Duplex Mode

Topics include:

• Speed and Duplex Mode Configuration Guidelines
• Setting the Interface Speed
• Setting the Interface Duplex Mode
• Displaying the Interface Speed and Duplex Mode Configuration
• Adding a Description for an Interface

Speed and Duplex Mode Configuration Guidelines

NoteYou do not configure the client device for autonegotiation. Instead, you configure the switch with the speed, or range of speeds, that you want to autonegotiate. You do not configure the client device for autonegotiation. Instead, you configure the switch with the speed, or range of speeds, that you want to autonegotiate.

You can configure the interface speed and duplex mode parameters to auto and allow the Catalyst 4500 series switch to negotiate the interface speed and duplex mode between interfaces. If you decide to configure the interface speed and duplex commands manually, consider the following:

• If you enter the no speed command, the switch automatically configures both interface speed and duplex to auto.
• When you set the interface speed to 1000 (Mbps) or auto 1000, the duplex mode is full duplex. You cannot change the duplex mode.
• If the interface speed is set to 10 or 100, the duplex mode is set to half duplex by default unless you explicitly configure it.

Setting the Interface Speed

If you set the interface speed to auto on a 10/100-Mbps Ethernet interface, speed and duplex are autonegotiated. The forced 10/100 autonegotiation feature allows you to limit interface speed auto negotiation up to 100 Mbps on a 10/100/1000BASE-T port.

To set the port speed for a 10/100-Mbps Ethernet interface, perform this task:

This example shows how to set the interface speed to 100 Mbps on the Fast Ethernet interface 5/4:

This example shows how to allow Fast Ethernet interface 5/4 to autonegotiate the speed and duplex mode:

NoteThe proceeding cli is analogous to speed auto 10 100. The proceeding cli is analogous to speed auto 10 100.

This example shows how to limit the interface speed to 10 and 100 Mbps on the Gigabit Ethernet interface 1/1 in auto-negotiation mode:

This example shows how to limit speed negotiation to 100 Mbps on the Gigabit Ethernet interface 1/1:

NoteTurning off autonegotiation on a Gigabit Ethernet interface results in the port being forced into 1000 Mbps and full-duplex mode. Turning off autonegotiation on a Gigabit Ethernet interface results in the port being forced into 1000 Mbps and full-duplex mode.

To turn off the port speed autonegotiation for Gigabit Ethernet interface 1/1, perform this task:

To restore autonegotiation, enter the no speed nonegotiate command in the interface configuration mode.

NoteFor the blocking ports on the WS-X4416 module, do not set the speed to autonegotiate. For the blocking ports on the WS-X4416 module, do not set the speed to autonegotiate.

Setting the Interface Duplex Mode

NoteWhen the interface is set to 1000 Mbps, you cannot change the duplex mode from full duplex to half duplex. When the interface is set to 1000 Mbps, you cannot change the duplex mode from full duplex to half duplex.

To set the duplex mode of a Fast Ethernet interface, perform this task:

This example shows how to set the interface duplex mode to full on Fast Ethernet interface 5/4:

Displaying the Interface Speed and Duplex Mode Configuration

To display the interface speed and duplex mode configuration for an interface, enter this command:

This example shows how to display the interface speed and duplex mode of Fast Ethernet interface 6/1:

Adding a Description for an Interface

You can add a description about an interface to help you remember its function. The description appears in the output of the following commands: show configuration , show running-config , and
show interfaces .

To add a description for an interface, enter the following command:

This example shows how to add a description on Fast Ethernet interface 5/5:

Configuring Flow Control

Gigabit Ethernet ports use flow control to slow down the transmission of incoming packets. If a buffer on a Gigabit Ethernet port runs out of space, the port transmits a special packet that requests remote ports to delay sending packets for a period of time. The port can also receive this special packet from its link partner for the same purpose. This special packet is called a pause frame.

The default settings for Gigabit Ethernet interfaces are as follows:

• Sending pause frames is off—Non-oversubscribed Gigabit Ethernet interfaces.
• Receiving pause frames is desired—Non-oversubscribed Gigabit Ethernet interfaces.
• Sending pause frames is on—Oversubscribed Gigabit Ethernet interfaces.
• Receiving pause frames is desired—Oversubscribed Gigabit Ethernet i nterfaces

The default settings for 10-Gigabit Ethernet interfaces are as follows:

• Sending pause frames is off.
• Receiving pause frames is on.

Notedesired is not a flow control option on the 10-Gigabit Ethernet interfaces. desired is not a flow control option on the 10-Gigabit Ethernet interfaces.

To configure flow control, perform this task:

This example shows how to configure flow control on an oversubscribed Gigabit Ethernet port 7/5:

This example shows the output of the show interfaces and show flowcontrol commands on an non-oversubscribed Gigabit Ethernet port 5/5:

This example shows the output of the show interfaces and show flowcontrol commands on an unsupported Fast Ethernet port 3/5:

Configuring Jumbo Frame Support

These sections describe jumbo frame support:

• Ports and Modules That Support Jumbo Frames
• Jumbo Frame Support
• Configuring MTU Sizes

Ports and Modules That Support Jumbo Frames

The following ports and modules support jumbo frames:

• Supervisor uplink ports
• WS-C4500X ports
• WS-X4306-GB: all ports
• WS-X4232-GB-RJ: ports 1-2
• WS-X4418-GB: ports 1-2
• WS-X4412-2GB-TX: ports 13-14
• WS-X4506-GB-T
• the 4648-GB-RJ45V
• WS-X4648-GB+RJ45V
• WS-X4648-RJ45V-E
• WS-X4648-RJ45V+E
• WS-X4706-10GE

Jumbo Frame Support

These sections describe jumbo frame support:

• Maximum Transmission Units
• Jumbo Frame Support Overview
• Ethernet Ports
• VLAN Interfaces

Maximum Transmission Units

The Catalyst 4500 series switch allows you to configure a maximum of 32 different maximum transmission unit (MTU) sizes system wide. This means that the maximum number of different MTU sizes that you can configure with the system mtu, mtu, ip mtu, and ipv6 mtu command on all Layer 2 and Layer 3 interfaces combined is 32.

Also, the system stores the IPv4 and IPv6 MTU sizes configured on an interface separately. For every system mtu command or per interface mtu command, two separate MTU values are stored, one for IPv4 and one for IPv6. This further reduces the number of slots available (out of 32). However, only a single MTU value is stored for each ip mtu and ipv6 mtu commands.

If the new MTU value you are configuring is already present in the system (that is, configured on some other interface), then no new slot(s) are allocated to store it again.

If the maximum limit of 32 is reached and an attempt is made to configure a new MTU size on a new interface, the system only allows configuration to proceed if the new MTU size has previously been configured on some interface. Otherwise, an error message is displayed and the default MTU size is assigned to the interface being configured.

Jumbo Frame Support Overview

A jumbo frame is a frame larger than the default Ethernet size. Enable jumbo frame support by configuring a larger-than-default MTU size on a port or interface.

Catalyst 4500 series switch Ethernet LAN ports configured with a nondefault MTU size accept frames containing packets with a size between 1500 and 9216 bytes (including Ethernet payload, header and trailer). (The maximum MTU size for a Catalyst 4948 series switch is 9198 bytes (not including header and trailer.)) With a nondefault MTU size configured, the packet size of ingress frames is checked. If the packet is larger than the configured MTU, it is dropped.

For traffic that needs to be routed, the MTU of the egress port is checked. If the MTU is smaller than the packet size, the packet is forwarded to the CPU. If the “do not fragment bit” is not set, it is fragmented. Otherwise, the packet is dropped.

NoteJumbo frame support does not fragment Layer 2 switched packets. Jumbo frame support does not fragment Layer 2 switched packets.

The Catalyst 4500 series switch does not compare the packet size with the MTU at the egress port, but jumbo frames are dropped in ports that do not support them. The frames can be transmitted in ports that do support jumbo frames, even though the MTU is not configured to jumbo size.

NoteJumbo frame support is only configured per interface; jumbo frame support cannot be configured globally. Jumbo frame support is only configured per interface; jumbo frame support cannot be configured globally.

Ethernet Ports

These sections describe configuring nondefault MTU sizes on Ethernet ports:

• Ethernet Port Overview
• Layer 3 and Layer 2 EtherChannels

Ethernet Port Overview

Starting with Cisco IOS Release 12.2(25)EW, configuring a nondefault MTU size on certain Ethernet ports limits the size of ingress packets. The MTU does not impact the egress packets.

Prior to Cisco IOS Release 12.1(13)EW, you could configure the MTU size only on Gigabit Ethernet.

Layer 3 and Layer 2 EtherChannels

Starting with Release Cisco IOS Release 12.2(25)EW, you could configure all the interfaces in an EtherChannel provided that they have the same MTU. Changing the MTU of an EtherChannel changes the MTU of all member ports. If the MTU of a member port cannot be changed to the new value, that port is suspended (administratively shut down). A port cannot join an EtherChannel if the port has a different MTU. If a member port of an EtherChannel changes MTU, the member port is suspended.

VLAN Interfaces

If switch ports reside in the same VLAN, either configure all of the switch ports to handle jumbo frames and support the same MTU size, or configure none of them. However, such uniformity of MTU size in the same VLAN is not enforced.

When a VLAN has switch ports with different MTU size, packets received from a port with a larger MTU might be dropped when they are forwarded to a port with a smaller MTU.

If the switch ports in a VLAN have jumbo frames enabled, the corresponding SVI can have jumbo frames enabled. The MTU of an SVI should always be smaller than the smallest MTU among all the switch ports in the VLAN, but this condition is not enforced.

The MTU of a packet is not checked on the ingress side for an SVI; it is checked on the egress side of an SVI. If the MTU of a packet is larger than the MTU of the egress SVI, the packet is sent to the CPU for fragmentation processing. If the “do not fragment” bit is not set, the packet is fragmented. Otherwise, the packet is dropped.

Configuring MTU Sizes

To configure the MTU size, perform this task:

NoteWhen you remove a line card, and then reinsert the card, some or all of the MTU values configured on the ports of that line card may be unconfigured. This occurs if the system wide limit of 32 different MTUs is reached while the card is removed. Upon reinserting the line card, the system attempts to reapply the MTU configuration on the ports. If this attempt fails, the MTU values are set to the default. When you remove a line card, and then reinsert the card, some or all of the MTU values configured on the ports of that line card may be unconfigured. This occurs if the system wide limit of 32 different MTUs is reached while the card is removed. Upon reinserting the line card, the system attempts to reapply the MTU configuration on the ports. If this attempt fails, the MTU values are set to the default.

NoteWhen configuring the MTU size for VLAN interfaces and Layer 3 and Layer 2 Ethernet ports, note that the supported MTU values are from 1500 to 9198 bytes. When configuring the MTU size for VLAN interfaces and Layer 3 and Layer 2 Ethernet ports, note that the supported MTU values are from 1500 to 9198 bytes.

This example shows how to configure the MTU size on Gigabit Ethernet port 1/1:

Interacting with Baby Giants

The baby giants feature, introduced in Cisco IOS Release 12.1(12c)EW, uses the global command system mtu size to set the global baby giant MTU. This feature also allows certain interfaces to support Ethernet payload size of up to 1552 bytes.

Both the system mtu command and the per-interface mtu command can operate on interfaces that can support jumbo frames, but the per-interface mtu command takes precedence.

For example, before setting the per-interface MTU for interface gi1/1, you enter the system mtu 1550 command to change the MTU for gi1/1 to 1550 bytes. You enter the per-interface mtu command to change the MTU for gi1/1 to 9198 bytes. If you change the baby giant MTU to 1540 bytes with the command system mtu 1540, the MTU for gi1/1 remains unchanged at 9198 bytes.

Configuring the Port Debounce Timer

NoteYou can only configure port debounce on 10-Gigabit Ethernet ports. You can only configure port debounce on 10-Gigabit Ethernet ports.

The port debounce timer suppresses notification of short link-down events. Link-down events that are shorter than the port debounce timer are not notified to Layer 2 or Layer 3 protocols, decreasing traffic loss due to network reconfiguration. You can configure the port debounce timer separately on each LAN port.

To configure the debounce timer on a port, perform this task:

NoteThe default time is 10ms for E-series supervisor engines and line cards. The default time is 10ms for E-series supervisor engines and line cards.

When configuring the debounce timer on a port, you can increase the port debounce timer value between 10 milliseconds and 5000 milliseconds on the 10-Gigabit Ethernet ports.

This example shows how to enable the port debounce timer on 10-Gigabit Ethernet port 2/1 and to accept the default value (10 ms):

This example shows how to enable the port debounce timer of 5000 ms on 10-Gigabit Ethernet port 2/2 and to verify the setting:

Configuring Auto-MDIX on a Port

When automatic medium-dependent-interface crossover (auto-MDIX) is enabled on an port, the port automatically detects the required cable connection type (straight through or crossover) and configures the connection appropriately. When connecting switches 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 switches or repeaters. With auto-MDIX enabled, use either type of cable to connect to other devices; 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. When you enable auto-MDIX, you must also set the speed on the port to auto so that for the feature to operate correctly. auto-MDIX is supported on copper media ports. It is not supported on fiber media ports.

NoteThe following line cards support Auto-MDIX by default, when port auto-negotiation is enabled: WS-X4424-GB-RJ45, WS-X4448-GB-RJ45,WS-X4548-GB-RJ45 and WS-X4412-2GB-T. You cannot disable them with the mdix command. The following line cards support Auto-MDIX by default, when port auto-negotiation is enabled: WS-X4424-GB-RJ45, WS-X4448-GB-RJ45,WS-X4548-GB-RJ45 and WS-X4412-2GB-T. You cannot disable them with the mdix command.

NoteThe following line cards do not support Auto-MDIX, neither by default nor by CLI: WS-X4548-GB-RJ45V, WS-X4524-GB-RJ45V, WS-X4506-GB-T,WS-X4148-RJ, WS-X4248-RJ21V, WS-X4248-RJ45V, WS-X4224-RJ45V and WS-X4232-GB-RJ. The following line cards do not support Auto-MDIX, neither by default nor by CLI: WS-X4548-GB-RJ45V, WS-X4524-GB-RJ45V, WS-X4506-GB-T,WS-X4148-RJ, WS-X4248-RJ21V, WS-X4248-RJ45V, WS-X4224-RJ45V and WS-X4232-GB-RJ.

NoteThe following line cards support Auto-MDIX through the CLI on their copper media ports: WS-X4124-RJ45, WS-X4148-RJ45 (hardware revision 3.0 or higher), and WS-X4232-GB-RJ45 (hardware revision 3.0, or higher), WS-X4920-GE-RJ45, WS-4648-RJ45V+E, WS-X4748-UPOE+E and WS-X4748-RJ45+E (Auto-MDIX support when inline power is disabled on the port). The following line cards support Auto-MDIX through the CLI on their copper media ports: WS-X4124-RJ45, WS-X4148-RJ45 (hardware revision 3.0 or higher), and WS-X4232-GB-RJ45 (hardware revision 3.0, or higher), WS-X4920-GE-RJ45, WS-4648-RJ45V+E, WS-X4748-UPOE+E and WS-X4748-RJ45+E (Auto-MDIX support when inline power is disabled on the port).

Table 7-3 shows the link states that results from auto-MDIX settings and correct and incorrect cabling.

To configure auto-MDIX on a port, perform this task:

To disable auto-MDIX, use the no mdix auto interface configuration command.

This example shows how to enable auto-MDIX on a port:

Displaying the Interface Auto-MDIX Configuration

To display the interface speed and duplex mode configuration for an interface, perform this task:

Depending on how the speed auto and the mdix auto commands are configured on a supported line card interface, the show interfaces command displays the following possible auto-MDIX statuses:

Table 7-4 shows the auto-MDIX setting and operational state and the status of auto-MDIX.

This example show s how to display the auto-MDIX configuration setting and its operational state on Fast Ethernet interface 6/1:

Shutting down a Module

To shut down a module safely, either enter the hw-module module stop command or press the OIR button for 5 seconds.

NoteThe hw-module module stop command is enabled only on the uplink modules of the WS-C4500X-32. The hw-module module stop command is enabled only on the uplink modules of the WS-C4500X-32.

The following example shows what happens if a module is up and you enter the hw-module module stop command:

The following example shows what happens if a module is already stopped and you enter the hw-module module stop command:

Booting a Module After if it has been Stopped

To bring up a module that has been stopped using the hw-module module number stop command or by pressing the OIR button, you either enter the hw-module module number start command or physically remove and reinsert.

The following example shows what happens if a module has been stopped and you enter this command:

The following example shows what happens if a module has not been stopped and you enter this command:

Common Scenarios

Table 7-5 lists the common scenarios associated with an OIR on a WS-4500X-32.

Monitoring Interface and Controller Status

The Cisco IOS software for the Catalyst 4500 series switch contains commands that you can enter at the EXEC prompt to display information about the interface, including the version of the software and the hardware, the controller status, and statistics about the interfaces. The following table lists some of the interface monitoring commands. (You can display the full list of show commands by entering the show ? command at the EXEC prompt.)

To display information about the interface, enter one of the following commands:

This example shows how to display the status of Fast Ethernet interface 5/5:

Clearing and Resetting the Interface

To clear the interface counters shown with the show interfaces command, enter this command:

This example shows how to clear and reset the counters on Fast Ethernet interface 5/5:

The clear counters command (without any arguments) clears all the current interface counters from all interfaces.

NoteThe The clear counters command does not clear counters retrieved with SNMP; it clears only those counters displayed with the EXEC show interfaces command.

Shutting Down and Restarting an Interface

You can disable an interface, which disables all functions on the specified interface and marks the interface as unavailable on all monitoring command displays. This information is communicated to other network servers through all dynamic routing protocols. The interface is not mentioned in any routing updates.

To shut down an interface and then restart it, perform this task:

This example shows how to shut down Fast Ethernet interface 5/5:

This example shows how to reenable Fast Ethernet interface 5/5:

To verify whether an interface is disabled, enter the EXEC show interfaces command. An interface that has been shut down appears as “administratively down.”

Configuring Interface Link Status and Trunk Status Events

You can configure interface link status and trunk status events. On the Catalyst 4500 series switch, the following interface logging event notifications are supported both globally and per interface:

• Enable or disable notification on the interface whenever its data link status is changed.
• Enable or disable notification on the trunk interface whenever its trunking status is changed.

Use the [no] logging event link-status use-global command to enable or disable the interface link status event. Use the [no] logging event trunk-status use-global command to enable or disable the interface trunk status event.

Each interface link status logging event can be configured in one of the following states:

• logging event link-status—Link status logging event is enabled explicitly on the interface regardless of the switch global setting.
• no logging event link-status—Link status logging event is disabled explicitly on the interface regardless of the switch global setting.
• logging event link-status use-global—Default link status logging event configuration on the interface; its configuration should follow the switch global link status logging event setting.

The interface trunk status logging event can be configured in the same configuration states.

Configuring Link Status Event Notification for an Interface

To enable or disable a link status logging event, enter one of the following commands:

Global Settings

You can also provide a global configuration for the corresponding logging event. A global configuration provides default logging settings for all interfaces. The [no] logging event link-status global command lets you enable or disable the interface link status logging for the entire switch. The [no] logging event trunk-status global command lets you enable disable interface trunk status logging for the entire switch.

Each interface link status logging event, if not configured at the interface level, uses the following global logging event setting:

• logging event link-status global—Link status logging event is enabled, if not configured on the interface.
• no logging event link-status global—Link status logging event is disabled, if not configured on the interface.

The interface trunk status logging event has similar global configurations.

Configuring a Switch Global Link Status Logging Event

To enable or disable the global link status logging event, enter one of the following commands:

Examples

The following example displays a summary of the operating states for the interface logging event using different combinations of global and interface logging settings:

The following example displays the configuration and logging message output for link status and trunk status logging events:

Resetting the Interface to the Default Configuration

If you have configured a interface with many command lines and you want to clear all the configuration on that interface, use the default interface global configuration command, as follows:

This command clears all the configurations and shut down the interface: