· A switch operating in standard mode does not support Layer 3 Ethernet interfaces, Layer 3 Ethernet subinterfaces, Layer 3 aggregate interfaces, or Layer 3 aggregate subinterfaces. For more information about the system operating mode commands, see Fundamentals Command Reference.

· When enhanced IRF is enabled on a switch operating in IRF mode, you cannot create Layer 3 Ethernet interfaces, Layer 3 Ethernet subinterfaces, Layer 3 aggregate interfaces, or Layer 3 aggregate subinterfaces on the switch. For more information about IRF, see IRF Configuration Guide.

Ethernet interface types

Your device supports the following types of Ethernet interfaces:

· Layer 2 Ethernet interfaces—Physical Ethernet interfaces operating at the data link layer (Layer 2) to switch traffic.

· Layer 3 Ethernet interfaces—Physical Ethernet interfaces operating at the network layer (Layer 3) to route traffic. You can assign an IP address to a Layer 3 Ethernet interface.

· Layer 3 Ethernet subinterfaces—Logical interfaces operating at the network layer. You can assign an IP address to a Layer 3 Ethernet subinterface. By creating subinterfaces on a Layer 3 Ethernet interface, you enable the interface to carry packets for multiple VLANs.

Configuring common Ethernet interface settings

IMPORTANT:

By default, Ethernet interfaces, VLAN-interfaces, and aggregate interfaces are down. To configure these interfaces, first bring up these interfaces by using the undo shutdown command.

This section describes the settings common to Layer 2 Ethernet interfaces and Layer 3 Ethernet interfaces or subinterfaces. For more information about the settings specific to Layer 2 Ethernet interfaces and Layer 3 Ethernet interfaces or subinterfaces, see "Configuring a Layer 2 Ethernet interface" and "Configuring a Layer 3 Ethernet interface or subinterface."

Configuring the operating mode and related parameters for a 10-GE interface

Configuring the operating mode

Some 10-GE interfaces support the following operating modes:

· LAN mode—In LAN mode, the 10-GE interface transmits Ethernet packets, and you must install a copper transceiver module to the interface to provide Ethernet network access.

· WAN mode—In WAN mode, the 10-GE interface transmits SDH frames, and you must install a fiber transceiver module to the interface to provide SDH network access. In this mode, the interface supports only point-to-point connections.

In WAN mode, a 10-GE interface encapsulates Ethernet packets in SDH frames, and a 10G POS interface encapsulates PPP packets in SDH frames. However, these two types of interfaces cannot communicate with each other in WAN mode, because they use different framing formats.

To configure a 10-GE interface to operate in LAN or WAN mode:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
1. Enter 10-GE interface view.	interface ten-gigabitethernet interface-number	N/A
2. Configure the 10-GE interface to operate in LAN or WAN mode.	port-mode { lan \| wan }	By default, a 10-GE interface operates in LAN mode.

Configuring the values of J0 and J1 overhead bytes

The J0 and J1 overhead bytes of SDH frames provide internetworking support between devices of different countries, regions, or vendors.

The Path Trace byte J0, a byte in the Regenerator Section Overhead, usually serves as a section access point identifier. The sending end keeps the connection with the receiving end by sending this byte repeatedly.

The Path Trace byte J1, a byte in the High-Order Path Overhead, usually serves as a high-order path access point identifier. J1 also enables two ends to keep connection in a similar way as J0.

To ensure smooth communication, the sending and receiving ends must have the same J0 and J1 bytes, respectively.

To configure the values of J0 and J1 overhead bytes:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter 10-GE interface view.	interface ten-gigabitethernet interface-number	N/A
3. Configure the 10-GE interface to operate in WAN mode.	port-mode wan	By default, a 10-GE interface operates in LAN mode.
4. Configure the value of the J0 or J1 byte.	flag { j0 \| j1 } sdh flag-value	By default, J0 and J1 bytes are padded with 0s.

Configuring basic settings of an Ethernet interface or subinterface

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 interface description.	description text	The default setting is in the format of interface-name Interface. For example, GigabitEthernet3/0/1 Interface.
4. Set the duplex mode of the Ethernet interface.	duplex { auto \| full \| half }	The default setting is full for 10-GE interfaces and auto for other Ethernet interfaces. Fiber ports do not support the half keyword.
5. Set the port speed.	speed { 10 \| 100 \| 1000 \| auto }	By default, the speed of an Ethernet interface is autonegotiated. Fiber ports do not support the 10 or 100 keyword. 10-GE interfaces do not support the speed setting.
6. Restore the default settings for the Ethernet interface.	default	N/A
7. Bring up the Ethernet interface.	undo shutdown	By default, an Ethernet interface is down.

Configuring an Ethernet subinterface

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Create an Ethernet subinterface.	interface interface-type interface-number.subnumber	N/A
3. Set the interface description.	description text	The default setting is interface-name Interface. For example, GigabitEthernet3/0/1.1 Interface.
4. Restore the default settings for the Ethernet subinterface.	default	N/A
5. Bring up the Ethernet subinterface.	undo shutdown	By default, an Ethernet subinterface is up.

To use an Ethernet subinterface to transmit and receive packets, you must associate it with a VLAN.

For the local and remote Ethernet subinterfaces to transmit traffic correctly, configure them with the same subinterface number and VLAN ID.

Configuring the link mode of an Ethernet interface

CAUTION:

After you change the link mode of an Ethernet interface, all settings of the Ethernet interface are restored to their defaults under the new link mode.

Ethernet interfaces can operate either as Layer 2 (in bridge mode) or Layer 3 Ethernet interfaces (in route mode). You can set the link mode to bridge or route for an Ethernet interface.

To change the link mode of an Ethernet interface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
1. Enter Ethernet interface view.	interface interface-type interface-number	N/A
2. Change the link mode of the Ethernet interface.	port link-mode { bridge \| route }	The default setting is bridge.

Configuring jumbo frame support

An Ethernet interface might receive some frames larger than the standard Ethernet frame size (called "jumbo frames") during high-throughput data exchanges, such as file transfers. Usually, an Ethernet interface discards jumbo frames. Jumbo frame support allows the interface to process jumbo frames within the specified range.

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 [ value ]	By default, the device allows jumbo frames within 9216 bytes to pass through. On LST1XP16LEB1 and LST1XP16LEC1 cards, the device allows jumbo frames within 8168 to pass through. If you set the value argument multiple times, the most recent configuration takes effect.

Configuring physical state change suppression on an Ethernet interface

The physical link state of an Ethernet interface is either up or down. Each time the physical link of a port goes up or comes down, the interface immediately reports the change to the CPU. The CPU then notifies the upper-layer protocol modules (such as routing and forwarding modules) of the change for guiding packet forwarding, and automatically generates traps and logs, informing the user to take corresponding actions.

To prevent frequent physical link flapping from affecting system performance, configure physical state change suppression to suppress the reporting of physical link state changes. The system reports physical layer changes only when the suppression interval expires.

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. Set the link-down event suppression interval.	link-delay delay-time	The default setting is 1 second. With this command configured, when the interface comes down, the link-down event is not reported to the CPU until the interface is still down when the suppression interval (delay-time) expires. When the interface goes up, the link-up event is immediately reported. This feature is not supported in the current software version. The feature is reserved for future support.
4. Set the link-up event suppression interval.	link-delay delay-time mode up	The default setting is 1 second. With this command configured, when the interface goes up, the link-up event is not reported to the CPU until the interface is still up when the suppression interval (delay-time) expires. When the interface comes down, the link-down event is immediately reported. This feature is not supported in the current software version. The feature is reserved for future support.
5. Set the link-updown event suppression interval.	link-delay delay-time mode updown	The default setting is 1 second. With this command configured, when the interface comes down or goes up, the link-updown event is not reported to the CPU until the interface is still down or up when the suppression interval (delay-time) expires.

If you configure the link-delay delay-time mode updown command multiple times, the most recent configuration takes effect.

Do not configure physical state change suppression on a port with MSTP enabled.

Performing a loopback test on an Ethernet interface

If an Ethernet interface does not work normally, you can perform a loopback test on it to identify the problem. An Ethernet interface in a loopback test does not forward data traffic.

Loopback tests fall into the following types:

· Internal loopback test—Tests all on-chip functions related to Ethernet interfaces.

· External loopback test—Tests the hardware of Ethernet interfaces. To perform an external loopback test on an Ethernet interface, connect a loopback plug to the Ethernet interface. The device sends test packets out of the interface, which are expected to loop over the plug and back to the interface. If the interface fails to receive any test packets, the hardware of the interface is faulty.

Configuration restrictions and guidelines

· On a physically down interface (displayed as in DOWN state), you can only perform an internal loopback test, and an external loopback test will fail. On an administratively shut down interface (displayed as in ADM or Administratively DOWN state), you cannot perform an internal or external loopback test.

· The speed, duplex, mdi, 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 perform a loopback test 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. Perform a loopback test.	loopback { external \| internal }	By default, no loopback test is performed. The external keyword is not supported in the current software version. The keyword is reserved for future support.

Configuring generic flow control on an Ethernet interface

To avoid packet drops 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.

With 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 the peer, it suspends sending packets.

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.	flow-control	By default, generic flow control is disabled on an Ethernet interface.

Setting the statistics polling interval

To set the statistics polling interval on an Ethernet interface:

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

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

To clear interface statistics, use the reset counters interface command.

Configuring a Layer 2 Ethernet interface

Configuring storm suppression

You can use the storm suppression function to limit the size of a particular type of traffic (broadcast, multicast, or unknown unicast traffic) 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.

Configuration guidelines

· When you configure the suppression threshold in pps or kbps, the device converts the configured value into a multiple of a certain step (6400 for pps and 50 for kbps) supported by the chip. As a result, the actual suppression threshold may be different from the configured one. For the suppression threshold that takes effect, see the prompt on the device.

· On an interface, you can configure only one of the kbps and pps keywords. To switch between the kbps and pps keywords, you must first restore the broadcast, multicast, or unknown unicast suppression threshold to the default.

· On an interface, only one suppression threshold is supported for different types of traffic. For example, if you have configured the broadcast suppression threshold as 100 kbps by using the broadcast-suppression kbps 100 command on an interface, to configure the multicast suppression threshold and unknown unicast threshold on the interface, you can only use the multicast-suppression kbps 100 and unicast-suppression kbps 100 commands.

Configuration procedure

To set storm suppression thresholds on one or multiple Ethernet interfaces:

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 traffic is allowed to pass through an interface. The ratio argument is always 100.
4. Enable multicast suppression and set the multicast suppression threshold.	multicast-suppression { ratio \| pps max-pps \| kbps max-kbps }	By default, multicast traffic is allowed to pass through an interface. The ratio argument is always 100.
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 traffic is allowed to pass through an interface. The ratio argument is always 100.

Forcibly bringing up a fiber GE or 10-GE port

As shown in Figure 1, a fiber port uses separate fibers for transmitting and receiving packets. The physical state of the fiber port is up only when both transmit and receive fibers are present. If one of the fibers is disconnected, the fiber port does not work.

To enable a fiber port to forward traffic over a single link, you can use the port up-mode command. This command brings up a fiber port by force, even when no fiber links or optical modules are present. If one fiber link is present and up, the fiber port can forward packets over the link unidirectionally.

Figure 1 Forcibly bring up a fiber GE or 10-GE port

Configuration restrictions and guidelines

When you forcibly bring up a fiber GE or 10-GE port, follow these guidelines:

· Only 10-GE fiber ports operating in LAN mode and GE fiber ports support this feature. Copper ports do not support this feature.

· To enable this feature on a port, make sure the port is operating in bridge mode.

· The port up-mode command is mutually exclusive with any of the shutdown, speed, duplex, and loopback commands.

· After you forcibly bring up a fiber Ethernet port, the fiber port stays physically up regardless of whether or not an optical module or a fiber connection is present for the port.

· The fiber port cannot properly forward traffic if you install a transceiver module, 100/1000-Mbps transceiver module, or 100-Mbps transceiver module into the port and configure the port up-mode command. To solve the problem, use the undo port up-mode command on the fiber port.

Configuration procedure

To forcibly bring up a fiber GE or 10-GE port:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter fiber GE or 10-GE port view.	interface interface-type interface-number	N/A
3. Forcibly bring up the fiber GE or 10-GE port.	port up-mode	By default, a fiber Ethernet port is not forcibly brought up, and the physical state of a fiber port depends on the physical state of the fibers.

Setting the MDIX mode of an Ethernet interface

NOTE:

Fiber ports do not support the MDIX mode setting.

A physical Ethernet interface comprises 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.

To enable the interface to communicate with its peer, set the MDIX mode of the interface mode by using the following guidelines:

· Generally, 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, set the interface to operate in the MDIX mode different than its peer.

· When a crossover cable is used, set the interface to operate in the same MDIX mode as its peer, or set 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 { automidx \| mdi \| mdix }	By default, a copper Ethernet interface operates in auto mode to negotiate pin roles with its peer.

Configuring a Layer 3 Ethernet interface or subinterface

Setting the MTU for an Ethernet interface or subinterface

The value of maximum transmission unit (MTU) affects the fragmentation and reassembly of IP packets. Generally, you do not need to modify the MTU of an interface.

To set the MTU for an Ethernet interface or subinterface:

Step	Command	Remarks
1. Enter system view.	system-view	N/A
2. Enter Ethernet interface or subinterface view.	interface interface-type { interface-number \| interface-number.subnumber }	N/A
3. Set the MTU.	mtu size	The default setting is 1500 bytes.

Displaying and maintaining an Ethernet interface or subinterface

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 \| interface-number.subnumber ] ]
Display traffic rate statistics of interfaces in up state over the last sampling interval.	display counters rate { inbound \| outbound } interface [ interface-type [ interface-number \| interface-number.subnumber ] ]
Display the operational and status information of the specified interface or all interfaces.	display interface [ interface-type [ interface-number \| interface-number.subnumber ] ]
Display summary information about the specified interface or all interfaces.	display interface [ interface-type [ interface-number \| interface-number.subnumber ] ] brief [ description ]
Display information about dropped packets on the specified interface or all interfaces.	display packet-drop { interface [ interface-type [ interface-number ] ] \| summary }
Clear the interface or subinterface statistics.	reset counters interface [ interface-type [ interface-number \| interface-number.subnumber ] ]
Clear the statistics of dropped packets on the specified interfaces.	reset packet-drop interface [ interface-type [ interface-number ] ]

03-Interface Configuration Guide

Configuring Ethernet interfaces

Configuring common Ethernet interface settings

Configuring the operating mode

Configuring the values of J0 and J1 overhead bytes

Configuring an Ethernet interface

Configuring an Ethernet subinterface

Configuration restrictions and guidelines

Configuration procedure

Configuring storm suppression

Configuration guidelines

Configuration procedure

Forcibly bringing up a fiber GE or 10-GE port

Configuration restrictions and guidelines

Configuration procedure

Configuring a Layer 3 Ethernet interface or subinterface

Setting the MTU for an Ethernet interface or subinterface

Displaying and maintaining an Ethernet interface or subinterface

Intelligent Terminal Products

Product Support Services

Technical Service Solutions

Resource Center

Policy

Online Help

Become a Partner

Partner Policy & Program

Global Learning

Partner Sales Resources

Service Business

News & Events

Contact Us