Contents

Configuring Ethernet interfaces· 1

Ethernet interface naming conventions· 1

Configuring a management Ethernet interface· 1

Configuring common Ethernet interface settings· 1

Configuring basic settings of an Ethernet interface· 1

Configuring jumbo frame support 2

Configuring physical state change suppression on an Ethernet interface· 3

Enabling loopback testing on an Ethernet interface· 4

Configuring generic flow control on an Ethernet interface· 4

Enabling energy saving features on an Ethernet interface· 5

Setting the statistics polling interval 6

Configuring storm suppression· 6

Configuring a Layer 2 Ethernet interface· 7

Configuring storm control on an Ethernet interface· 7

Setting the MDIX mode of an Ethernet interface· 8

Testing the cable connection of an Ethernet interface· 9

Enabling bridging on an Ethernet interface· 9

Displaying and maintaining an Ethernet interface· 10

Configuring Ethernet interfaces

The switch series supports Ethernet interfaces, management Ethernet interfaces, console interfaces, and USB interfaces. For the interface types and the number of interfaces supported by a switch model, see the installation guide.

This chapter describes how to configure management Ethernet interfaces and Ethernet interfaces.

Ethernet interface naming conventions

The Ethernet interfaces are named in the format of interface type A/B/C. The letters that follow the interface type represent the following elements:

·     A—IRF member ID. If the switch is not in an IRF fabric, A is 1 by default.

·     B—Card slot number. 0 indicates the interface is a fixed interface of the switch.

·     C—Port index.

Configuring a management Ethernet interface

A management interface uses an RJ-45 connector. You can connect the interface to a PC for software loading and system debugging, or connect it to a remote NMS for remote system management.

To configure a management Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter management Ethernet interface view.	interface M-GigabitEthernet interface-number	N/A
3.     (Optional.) Set the interface description.	description text	The default setting is M-GigabitEthernet0/0/0 Interface.
4.     (Optional.) Shut down the interface.	shutdown	By default, the management Ethernet interface is up.

 

Configuring common Ethernet interface settings

Configuring basic settings of an Ethernet interface

You can configure an Ethernet interface to operate in one of the following duplex modes:

·     Full-duplex mode—The interface can send and receive packets simultaneously.

·     Autonegotiation mode—The interface negotiates a duplex mode with its peer.

You can set the speed of an Ethernet interface or enable it to automatically negotiate a speed with its peer.

Configuring an Ethernet interface

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Set the description for the Ethernet interface.	description text	The default setting is interface-name Interface, for example, Ten-GigabitEthernet1/0/1 Interface.
4.     Set the duplex mode for the Ethernet interface.	duplex { auto | full }	By default, the duplex mode is auto for Ethernet interfaces.
5.     Set the speed for the Ethernet interface.	speed { 100 | 2500 | 5000 | 1000 | 10000 | auto }	The default setting is auto for Ethernet interfaces. Support for the keywords depends on the interface type. For more information, use the speed ? command in interface view. The 2.5G/1000/100BASE-T autosensing Ethernet ports on an S5150-24S-PWR-EI switch do not comply with the IEEE 802.3bz standard, and cannot negotiate the speed to 2.5G with interfaces that comply with the standard.
6.     Set the expected bandwidth for the Ethernet interface.	bandwidth bandwidth-value	By default, the expected bandwidth (in kbps) is the interface baud rate divided by 1000.
7.     Restore the default settings for the Ethernet interface.	default	N/A
8.     Bring up the Ethernet interface.	undo shutdown	By default, Ethernet interfaces are in up state. The loopback and shutdown commands are mutually exclusive.

 

Configuring jumbo frame support

An Ethernet interface might receive frames larger than the standard Ethernet frame size during high-throughput data exchanges, such as file transfers. These frames are called jumbo frames.

The Ethernet interface processes jumbo frames in the following ways:

·     When the Ethernet interface is configured to deny jumbo frames, the Ethernet interface discards jumbo frames.

·     When the Ethernet interface is configured with jumbo frame support, the Ethernet interface performs the following operations:

¡     Processes jumbo frames within the specified length.

¡     Discards jumbo frames that exceed the specified length.

To configure jumbo frame support in interface view:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Configure jumbo frame support.	jumboframe enable [ size ]	By default, the switch allows jumbo frames within 10000 bytes to pass through all Ethernet interfaces.

 

Configuring physical state change suppression on an Ethernet interface

IMPORTANT: Do not enable this feature on an interface that has RRPP, spanning tree protocols, or Smart Link enabled.

 

The physical link state of an Ethernet interface is either up or down. Each time the physical link of an interface comes up or goes down, the interface immediately reports the change to the CPU. The CPU then performs the following operations:

·     Notifies the upper-layer protocol modules (such as routing and forwarding modules) of the change for guiding packet forwarding.

·     Automatically generates traps and logs to inform users to take the correct actions.

To prevent frequent physical link flapping from affecting system performance, configure physical state change suppression. You can configure this feature to suppress only link-down events, only link-up events, or both. If an event of the specified type still exists when the suppression interval expires, the system reports the event.

When you configure this feature, follow these guidelines:

·     To suppress only link-down events, configure the link-delay [ msec ] delay-time command.

·     To suppress only link-up events, configure the link-delay [ msec ] delay-time mode up command.

·     To suppress both link-down and link-up events, configure the link-delay [ msec ] delay-time mode updown command.

The link-delay command will not take effect if you execute the shutdown or undo shutdown command before the suppression interval expires.

As a best practice for an interface to discover LLDP neighbors, do not change the interface rate after the link-delay command is configured.

To configure physical state change suppression on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Configure physical state change suppression.	link-delay [ msec ] delay-time [ mode { up | updown }]	By default, the link-down or link-up event is immediately reported to the CPU. If you configure this command multiple times on an Ethernet interface, the most recent configuration takes effect.

 

Enabling loopback testing on an Ethernet interface

CAUTION: After you enable this feature on an Ethernet interface, the interface cannot forward data traffic correctly.

 

Perform this task to determine whether an Ethernet link works correctly.

Loopback testing includes the following types:

·     Internal loopback testing—Tests the device where the Ethernet interface resides. The Ethernet interface sends outgoing packets back to the local device. If the device fails to receive the packets, the device fails.

·     External loopback testing—Tests the inter-device link. The Ethernet interface sends incoming packets back to the remote device. If the remote device fails to receive the packets, the inter-device link fails.

Configuration restrictions and guidelines

·     On an administratively shut down Ethernet interface (displayed as in ADM or Administratively DOWN state), you cannot perform an internal or external loopback test.

·     The speed, duplex, mdix-mode, and shutdown commands are not available during a loopback test.

·     During a loopback test, the Ethernet interface operates in full duplex mode. When a loopback test is complete, the port returns to its duplex setting..

Configuration procedure

To enable loopback testing on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Enable loopback testing.	loopback { external | internal }	By default, no loopback test is performed.

 

Configuring generic flow control on an Ethernet interface

To avoid dropping packets on a link, you can enable generic flow control at both ends of the link. When traffic congestion occurs at the receiving end, the receiving end sends a flow control (Pause) frame to ask the sending end to suspend sending packets. Generic flow control includes the following types:

·     TxRx-mode generic flow control—Enabled by using the flow-control command. With TxRx-mode generic flow control enabled, an interface can both send and receive flow control frames:

¡     When congestion occurs, the interface sends a flow control frame to its peer.

¡     When the interface receives a flow control frame from its peer, it suspends sending packets to its peer.

·     Rx-mode generic flow control—Enabled by using the flow-control receive enable command. With Rx-mode generic flow control enabled, an interface can receive flow control frames, but it cannot send flow control frames:

¡     When congestion occurs, the interface cannot send flow control frames to its peer.

¡     When the interface receives a flow control frame from its peer, it suspends sending packets to its peer.

To handle unidirectional traffic congestion on a link, configure the flow-control receive enable command at one end and the flow-control command at the other end. To enable both ends of a link to handle traffic congestion, configure the flow-control command at both ends.

To enable generic flow control on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Enable generic flow control.	·     Enable TxRx-mode generic flow control: flow-control ·     Enable Rx-mode generic flow control: flow-control receive enable	By default, generic flow control is disabled on an Ethernet interface.

 

Enabling energy saving features on an Ethernet interface

IMPORTANT: Fiber ports do not support these features.

 

Enabling auto power-down on an Ethernet interface

When an Ethernet interface with auto power-down enabled has been down for a certain period of time, both of the following events occur:

·     The device automatically stops supplying power to the Ethernet interface.

·     The Ethernet interface enters the power save mode.

The time period depends on the chip specifications and is not configurable.

When the Ethernet interface comes up, both of the following events occur:

·     The device automatically restores power supply to the Ethernet interface.

·     The Ethernet interface restores to its normal state.

To enable auto power-down on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Enable auto power-down on the Ethernet interface.	port auto-power-down	By default, auto power-down is disabled on an Ethernet interface.

 

Enabling EEE on an Ethernet interface

With Energy Efficient Ethernet (EEE) enabled, a link-up interface enters low power state if it has not received any packet for a period of time. The time period depends on the chip specifications and is not configurable. When a packet arrives later, the device automatically restores power supply to the interface and the interface restores to the normal state.

To enable EEE on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Enable EEE on the Ethernet interface.	eee enable	By default, EEE is disabled on an Ethernet interface.

 

Setting the statistics polling interval

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Set the statistics polling interval for the Ethernet interface.	flow-interval interval	By default, the statistics polling interval is 300 seconds.

 

To display the interface statistics collected in the last statistics polling interval, use the display interface command.

Configuring storm suppression

The storm suppression feature ensures that the size of a particular type of traffic (broadcast, multicast, or unknown unicast traffic) does not exceed the threshold on an interface. When the broadcast, multicast, or unknown unicast traffic on the interface exceeds this threshold, the system discards packets until the traffic drops below this threshold.

Both storm suppression and storm control can suppress storms on an interface. Storm suppression uses the chip to suppress traffic. Storm suppression has less impact on the device performance than storm control, which uses software to suppress traffic.

Configuration restrictions and guidelines

When you configure storm suppression, follow these restrictions and guidelines:

·     For the traffic suppression result to be determined, do not configure storm control together with storm suppression for the same type of traffic. For more information about storm control, see "Configuring storm control on an Ethernet interface."

·     When you configure the suppression threshold in kbps, the actual suppression threshold might be different from the configured one as follows:

¡     If the configured value is smaller than 64, the value of 64 takes effect.

¡     If the configured value is greater than 64 but not an integer multiple of 64, the integer multiple of 64 that is greater than and closest to the configured value takes effect.

For the suppression threshold that takes effect, see the prompt on the device.

Configuration procedure

To set storm suppression thresholds on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Enable broadcast suppression and set the broadcast suppression threshold.	broadcast-suppression { ratio | pps max-pps | kbps max-kbps }	By default, broadcast suppression is disabled.
4.     Enable multicast suppression and set the multicast suppression threshold.	multicast-suppression { ratio | pps max-pps | kbps max-kbps }	By default, multicast suppression is disabled.
5.     Enable unknown unicast suppression and set the unknown unicast suppression threshold.	unicast-suppression { ratio | pps max-pps | kbps max-kbps }	By default, unknown unicast suppression is disabled.

 

Configuring a Layer 2 Ethernet interface

Configuring storm control on an Ethernet interface

About storm control

Storm control compares broadcast, multicast, and unknown unicast traffic regularly with their respective traffic thresholds on an Ethernet interface. For each type of traffic, storm control provides a lower threshold and an upper threshold.

Depending on your configuration, when a particular type of traffic exceeds its upper threshold, the interface performs either of the following operations:

·     Blocks this type of traffic and forwards other types of traffic—Even though the interface does not forward the blocked traffic, it still counts the traffic. When the blocked traffic drops below the lower threshold, the interface begins to forward the traffic.

·     Goes down automatically—The interface goes down automatically and stops forwarding any traffic. When the blocked traffic drops below the lower threshold, the interface does not automatically come up. To bring up the interface, use the undo shutdown command or disable the storm control feature.

You can configure an Ethernet interface to output threshold event traps and log messages when monitored traffic meets one of the following conditions:

·     Exceeds the upper threshold.

·     Drops below the lower threshold.

Both storm suppression and storm control can suppress storms on an interface. Storm suppression uses the chip to suppress traffic. Storm suppression has less impact on the device performance than storm control, which uses software to suppress traffic.

Storm control uses a complete polling cycle to collect traffic data, and analyzes the data in the next cycle. An interface takes one to two polling intervals to take a storm control action.

Configuration restrictions and guidelines

For the traffic suppression result to be determined, do not configure storm control together with storm suppression for the same type of traffic. For more information about storm suppression, see "Configuring storm suppression."

Configuration procedure

To configure storm control on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     (Optional.) Set the statistics polling interval of the storm control module.	storm-constrain interval interval	The default setting is 10 seconds. For network stability, use the default or set a longer statistics polling interval.
3.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
4.     (Optional.) Enable storm control, and set the lower and upper thresholds for broadcast, multicast, or unknown unicast traffic.	storm-constrain { broadcast | multicast | unicast } { pps | kbps | ratio } max-pps-values min-pps-values	By default, storm control is disabled.
5.     Set the control action to take when monitored traffic exceeds the upper threshold.	storm-constrain control { block | shutdown }	By default, storm control is disabled.
6.     (Optional.) Enable the Ethernet interface to output log messages when it detects storm control threshold events.	storm-constrain enable log	By default, the Ethernet interface outputs log messages when monitored traffic exceeds the upper threshold or drops below the lower threshold.
7.     (Optional.) Enable the Ethernet interface to send storm control threshold event traps.	storm-constrain enable trap	By default, the Ethernet interface sends traps when monitored traffic exceeds the upper threshold or drops below the lower threshold from the upper threshold.

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Setting the MDIX mode of an Ethernet interface

IMPORTANT: Fiber ports do not support the MDIX mode setting.

 

A physical Ethernet interface has eight pins, each of which plays a dedicated role. For example, pins 1 and 2 transmit signals, and pins 3 and 6 receive signals. You can use both crossover and straight-through Ethernet cables to connect copper Ethernet interfaces. To accommodate these types of cables, a copper Ethernet interface can operate in one of the following Medium Dependent Interface-Crossover (MDIX) modes:

·     MDIX mode—Pins 1 and 2 are receive pins and pins 3 and 6 are transmit pins.

·     MDI mode—Pins 1 and 2 are transmit pins and pins 3 and 6 are receive pins.

·     AutoMDIX mode—The interface negotiates pin roles with its peer.

 

NOTE: This feature does not take effect on pins 4, 5, 7, and 8 of physical Ethernet interfaces. ·     Pins 4, 5, 7, and 8 of interfaces operating at 10 Mbps or 100 Mbps do not receive or transmit signals. ·     Pins 4, 5, 7, and 8 of interfaces operating at 1000 Mbps or higher rates receive and transmit signals.

 

To enable a copper Ethernet interface to communicate with its peer, set the MDIX mode of the interface by following these guidelines:

·     Typically, set the MDIX mode of the interface to AutoMDIX. Set the MDIX mode of the interface to MDI or MDIX only when the device cannot determine the cable type.

·     When a straight-through cable is used, configure the interface to operate in an MDIX mode different than its peer.

·     When a crossover cable is used, perform one of the following tasks:

¡     Configure the interface to operate in the same MDIX mode as its peer.

¡     Configure either end to operate in AutoMDIX mode.

To set the MDIX mode of an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Set the MDIX mode of the Ethernet interface.	mdix-mode { automdix | mdi | mdix }	By default, a copper Ethernet interface operates in auto mode to negotiate pin roles with its peer.

 

Testing the cable connection of an Ethernet interface

IMPORTANT: If the link of an Ethernet interface is up, testing its cable connection will cause the link to go down and then come up.

 

NOTE: Fiber ports do not support this feature.

 

This feature tests the cable connection of an Ethernet interface and displays cable test result within 5 seconds. The test result includes the cable's status and some physical parameters. If any fault is detected, the test result shows the length from the local port to the faulty point.

To test the cable connection of an Ethernet interface:

 

Step	Command
1.     Enter system view.	system-view
2.     Enter Ethernet interface view.	interface interface-type interface-number
3.     Perform a test for the cable connected to the Ethernet interface.	virtual-cable-test

 

Enabling bridging on an Ethernet interface

By default, the device drops packets whose outgoing interface and incoming interface are the same.

To enable the device to forward such packets rather than drop them, enable the bridging feature in Ethernet interface view.

To enable bridging on an Ethernet interface:

 

Step	Command	Remarks
1.     Enter system view.	system-view	N/A
2.     Enter Ethernet interface view.	interface interface-type interface-number	N/A
3.     Enable bridging on the Ethernet interface.	port bridge enable	By default, bridging is disabled on an Ethernet interface.

 

Displaying and maintaining an Ethernet interface

Execute display commands in any view and reset commands in user view.

 

Task	Command
Display interface traffic statistics.	display counters { inbound | outbound } interface [ interface-type [ interface-number ]
Display traffic rate statistics of interfaces in up state over the last statistics polling interval.	display counters rate { inbound | outbound } interface [ interface-type [ interface-number ]
Display the operational and status information of the specified interfaces.	display interface [ interface-type [ interface-number ] ] [ brief [ description | down ] ]
Display information about dropped packets on the specified interfaces.	display packet-drop { interface [ interface-type [ interface-number ] ] | summary }
Display information about storm control on the specified interfaces.	display storm-constrain [ broadcast | multicast | unicast ] [ interface interface-type interface-number ]
Display the Ethernet module statistics.	display ethernet statistics slot slot-number
Clear interface statistics.	reset counters interface [ interface-type [ interface-number ]
Clear the statistics of dropped packets on the specified interfaces.	reset packet-drop interface [ interface-type [ interface-number ] ]
Clear the Ethernet module statistics.	reset ethernet statistics [ slot slot-number ]