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.

Configuring a management Ethernet interface

About a management 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.

Procedure

1. Enter system view.

system-view

2. Enter management Ethernet interface view.

interface M-GigabitEthernet interface-number

3. (Optional.) Set the interface description.

description text

The default setting is M-GigabitEthernet0/0/0 Interface.

4. (Optional.) Set the duplex mode.

duplex { auto | full | half }

By default, the duplex mode is auto for a management Ethernet interface.

5. (Optional.) Set the speed.

speed { 10 | 100 | 1000 | auto }

By default, a management Ethernet interface negotiates a speed with its peer.

6. (Optional.) Shut down the interface.

shutdown

By default, the management Ethernet interface is up.

CAUTION:

Executing the shutdown command on an interface will disconnect the link of the interface and interrupt communication. Use this command with caution.

Ethernet interface naming conventions

When the device is in an IRF fabric, Ethernet interfaces are named in the format of interface type A/B/C/D. When the device is not in an IRF fabric, 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.

· B—Card slot number.

· C—Subcard slot number.

· D—Port index.

Ethernet interface usage restrictions and guidelines

25-GE interface usage restrictions and guidelines

25-GE interfaces can operate at 25 Gbps, 10 Gbps, or 1 Gbps. 25-GE interfaces do not support speed or duplex mode autonegotiation. You must use the speed and duplex commands to ensure that the interfaces at both ends of a link operate in the same speed and duplex mode. An interface can come up only when the interface is configured with the same speed as its transceiver module or cable. Interfaces in the same group must have the same speed. When you modify the speed of an interface, the modification takes effect on all interfaces in the same group as the interface. When you modify the link mode (route or bridge) of an interface, the speed is restored to the default for the interface and the other interfaces in the same group.

25-GE interfaces are grouped as follows:

· For interfaces on an LSWM124TG2H interface module, four continuous interfaces starting from 1 are organized into one group.

· When you use the using twenty-fivegige command to split a 100-GE interface into four 25-GE breakout interfaces, the four breakout interfaces are organized into one group.

Interfaces in the same group on an LSWM124TG2H interface module must be configured with the same media type.

10-GE interface usage restrictions and guidelines

10-GE interfaces on a 10-GE expansion module installed in an LSXM1TGS24CGMODHD1 or LSXM1TGS24QGMODHB1 interface module do not support speed or duplex mode autonegotiation. For a 10-GE interface to operate at 1 Gbps, you must execute the speed 1000 and duplex full commands on both ends.

For a device connected to a peer device through an SFP-GE-T/SFP-GE-T-D module, when the device is rebooted, the peer interface will come up before the local interface comes up. As a result, packet loss occurs. To connect a device to a peer device through an aggregate interface, as a best practice, use a dynamic aggregate interface to avoid the preceding issue.

Configuring common Ethernet interface settings

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

Splitting a 100-GE interface and combining 10-GE breakout interfaces

About 100-GE interface splitting and 10-GE breakout interface combining

You can use a 100-GE interface as a single interface. To improve port density, reduce costs, and improve network flexibility, you can also split a 100-GE interface with a split-capable 40-GE transceiver module or cable installed into four 10-GE breakout interfaces. The 10-GE breakout interfaces support the same configuration and attributes as common 10-GE interfaces, except that they are numbered differently.

For example, you can split 100-GE interface HundredGigE 1/0/1 into four 10-GE breakout interfaces Ten-GigabitEthernet 1/0/1:1 through Ten-GigabitEthernet 1/0/1:4.

If you need higher bandwidth on a single interface, you can combine the 10-GE breakout interfaces into a 100-GE interface.

Restrictions and guidelines for 100-GE interface splitting and 10-GE breakout interface combining

This feature is supported only on the default MDC.

A 100-GE interface split into 10-GE breakout interfaces must use a dedicated cable. After you combine the 10-GE breakout interfaces, replace the dedicated cable with a dedicated 1-to-1 cable or a 100-GE transceiver module and optical fiber. For more information about the cable or transceiver module, see the installation guides.

To view interfaces capable of being spit, execute the display interface split-capable command.

As a best practice to ensure stability, reboot the device after configuration. When interfaces are being split or combined, do not reboot the MPU or perform an active/standby switchover.

Splitting a 100-GE interface into four 10-GE breakout interfaces

1. Enter system view.

system-view

2. Enter 100-GE interface view.

interface interface-type interface-number

3. Split the 100-GE interface into four 10-GE breakout interfaces.

using tengige

By default, a 100-GE interface is not split and operates as a single interface.

Combining four 10-GE breakout interfaces into a 100-GE interface

1. Enter system view.

system-view

2. Enter the view of any 10-GE breakout interface.

interface interface-type interface-number

3. Combine the multiple 10-GE breakout interfaces into a 100-GE interface.

using hundredgige

By default, a 10-GE breakout interface operates as a single interface.

Splitting a 100-GE interface and combining 25-GE breakout interfaces

About 100-GE interface splitting and 25-GE breakout interface combining

You can use a 100-GE interface as a single interface. To improve port density, reduce costs, and improve network flexibility, you can also split a 100-GE interface into four 25-GE breakout interfaces. The 25-GE breakout interfaces support the same configuration and attributes as common 25-GE interfaces, except that they are numbered differently.

For example, you can split 100-GE interface HundredGigE 1/0/1 into four 25-GE breakout interfaces Twenty-FiveGigE 1/0/1:1 through Twenty-FiveGigE 1/0/1:4.

If you need higher bandwidth on a single interface, you can combine the four 25-GE breakout interfaces into a 100-GE interface.

Restrictions and guidelines for 100-GE interface splitting and 25-GE breakout interface combining

This feature is supported only on the default MDC.

A 100-GE interface split into four 25-GE breakout interfaces must use a dedicated 1-to-4 cable. After you combine the four 25-GE breakout interfaces, replace the dedicated 1-to-4 cable with a dedicated 1-to-1 cable or a 100-GE transceiver module and optical fiber. For more information about the cable or transceiver module, see the installation guides.

To view interfaces capable of being spit, execute the display interface split-capable command.

As a best practice to ensure stability, reboot the device after configuration. When interfaces are being split or combined, do not reboot the MPU or perform an active/standby switchover.

Splitting a 100-GE interface into four 25-GE breakout interfaces

1. Enter system view.

system-view

2. Enter 100-GE interface view.

interface interface-type interface-number

3. Split the 100-GE interface into four 25-GE breakout interfaces.

using twenty-fivegige

By default, a 100-GE interface is not split and operates as a single interface.

Combining four 25-GE breakout interfaces into a 100-GE interface

1. Enter system view.

system-view

2. Enter the view of any 25-GE breakout interface.

interface interface-type interface-number

3. Combine the four 25-GE breakout interfaces into a 100-GE interface.

using hundredgige

By default, a 25-GE breakout interface operates as a single interface.

Splitting a 40-GE interface and combining 10-GE breakout interfaces

About 40-GE interface splitting and 10-GE breakout interface combining

You can use a 40-GE interface as a single interface. To improve port density, reduce costs, and improve network flexibility, you can also split a 40-GE interface into four 10-GE breakout interfaces. The 10-GE breakout interfaces support the same configuration and attributes as common 10-GE interfaces, except that they are numbered differently.

For example, you can split 40-GE interface FortyGigE 1/0/1 into four 10-GE breakout interfaces Ten-GigabitEthernet 1/0/1:1 through Ten-GigabitEthernet 1/0/1:4.

If you need higher bandwidth on a single interface, you can combine the four 10-GE breakout interfaces into a 40-GE interface.

Restrictions and guidelines for 40-GE interface splitting and 10-GE breakout interface combining

This feature is supported only on the default MDC.

A 40-GE interface split into four 10-GE breakout interfaces must use a dedicated 1-to-4 cable. After you combine the four 10-GE breakout interfaces, replace the dedicated 1-to-4 cable with a dedicated 1-to-1 cable or a 40-GE transceiver module. For more information about the cable or transceiver module, see the installation guides.

To view interfaces capable of being split, execute the display interface split-capable command.

As a best practice to ensure stability, reboot the device after the configuration. When interfaces are being split or combined, do not reboot the MPU or perform an active/standby switchover.

Splitting a 40-GE interface into four 10-GE breakout interfaces

1. Enter system view.

system-view

2. Enter 40-GE interface view.

interface interface-type interface-number

3. Split the 40-GE interface into four 10-GE breakout interfaces.

using tengige

By default, a 40-GE interface is not split and operates as a single interface.

Combining four 10-GE breakout interfaces into a 40-GE interface

1. Enter system view.

system-view

2. Enter the view of any 10-GE breakout interface.

interface interface-type interface-number

3. Combine the four 10-GE breakout interfaces into a 40-GE interface.

using fortygige

By default, a 10-GE breakout interface operates as a single interface.

Configuring basic settings of an Ethernet interface

About Ethernet interface basic settings

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.

Restrictions and guidelines

The shutdown, port up-mode, and loopback commands are mutually exclusive.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Set the description for the Ethernet interface.

description text

The default setting is interface-name Interface. For example, FortyGigE1/0/1 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 { 10 | 100 | 1000 | 10000 | 25000 | 40000 | 100000 | auto }

By default, an Ethernet interface negotiates a speed with its peer.

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. Bring up the Ethernet interface.

undo shutdown

By default, Ethernet interfaces are in down state.

Configuring basic settings of an Ethernet subinterface

Restrictions and guidelines for Ethernet subinterface basic settings

· Before creating a Layer 3 Ethernet subinterface for the S9800 switch series, the S12500-X switch series, or the S12500X-AF F cards, do not reserve a resource for the VLAN interface whose interface number is the subinterface number. After you reserve a VLAN interface resource, do not create a Layer 3 Ethernet subinterface whose subinterface number is the VLAN interface number. A Layer 3 Ethernet subinterface uses the VLAN interface resource in processing tagged packets whose VLAN ID matches the subinterface number. For more information about reserving resources for VLAN interfaces, see Layer 2—LAN Switching Configuration Guide.

· The shutdown, port up-mode, and loopback commands are mutually exclusive.

Procedure

1. Enter system view.

system-view

2. Create an Ethernet subinterface.

interface interface-type interface-number.subnumber

3. Set the description for the Ethernet subinterface.

description text

The default setting is interface-name Interface. For example, FortyGigE1/0/1.1 Interface.

4. Set the expected bandwidth for the Ethernet subinterface.

bandwidth bandwidth-value

By default, the expected bandwidth (in kbps) is the interface baud rate divided by 1000.

5. Bring up the Ethernet subinterface.

undo shutdown

By default, Ethernet subinterfaces are in up state.

Configuring the link mode of an Ethernet interface

About the link mode of an Ethernet interface

Interfaces on the device can operate either as Layer 2 or Layer 3 Ethernet interfaces. You can use commands to set the link mode to bridge or route.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Configure the link mode of the Ethernet interface.

port link-mode { bridge | route }

By default, all Ethernet interfaces on the device operate in bridge mode.

CAUTION:

After you change the link mode of an Ethernet interface, all commands (except the shutdown command) on the Ethernet interface are restored to their defaults in the new link mode.

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Configuring jumbo frame support

About jumbo frame

Jumbo frames are frames larger than 1536 bytes and are typically received by an Ethernet interface during high-throughput data exchanges, such as file transfers.

The Ethernet interface processes jumbo frames in the following ways:

· When the Ethernet interface is configured to deny jumbo frames (by using the undo jumboframe enable command), 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.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Configure jumbo frame support.

jumboframe enable [ size ]

By default, the device allows jumbo frames within 12288 bytes to pass through.

If you set the size argument multiple times, the most recent configuration takes effect.

Configuring physical state change suppression on an Ethernet interface

About physical state change suppression

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 to the CPU.

Restrictions and guidelines

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

You can configure different suppression intervals for link-up and link-down events.

If you configure this command multiple times for link-up or link-down events on an Ethernet interface, the most recent configuration takes effect.

The link-delay, dampening, and port link-flap protect enable commands are mutually exclusive on an Ethernet interface.

On an interface, you can configure different suppression intervals for link-up and link-down events. If you configure the link-delay command multiple times for link-up or link-down events, the most recent configuration takes effect.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Configure physical state change suppression.

link-delay [ msec ] delay-time [ mode { up | updown }]

By default, each time the physical link of a port goes up or comes down, the interface immediately reports the change to the CPU.

To suppress only link-down events, do not specify the mode keyword. To suppress only link-up events, specify the mode up keywords. To suppress both link-down and link-up events, specify the mode updown keywords.

Configuring dampening on an Ethernet interface

About dampening

The interface dampening feature uses an exponential decay mechanism to prevent excessive interface flapping events from adversely affecting routing protocols and routing tables in the network. Suppressing interface state change events protects the system resources.

If an interface is not dampened, its state changes are reported. For each state change, the system also generates an SNMP trap and log message.

After a flapping interface is dampened, it does not report its state changes to the CPU. For state change events, the interface only generates SNMP trap and log messages.

Parameters

· Penalty—The interface has an initial penalty of 0. When the interface flaps, the penalty increases by 1000 for each down event until the ceiling is reached. It does not increase for up events. When the interface stops flapping, the penalty decreases by half each time the half-life timer expires until the penalty drops to the reuse threshold.

· Ceiling—The penalty stops increasing when it reaches the ceiling.

· Suppress-limit—The accumulated penalty that triggers the device to dampen the interface. In dampened state, the interface does not report its state changes to the CPU. For state change events, the interface only generates SNMP traps and log messages.

· Reuse-limit—When the accumulated penalty decreases to this reuse threshold, the interface is not dampened. Interface state changes are reported to the upper layers. For each state change, the system also generates an SNMP trap and log message.

· Decay—The amount of time (in seconds) after which a penalty is decreased.

· Max-suppress-time—The maximum amount of time the interface can be dampened. If the penalty is still higher than the reuse threshold when this timer expires, the penalty stops increasing for down events. The penalty starts to decrease until it drops below the reuse threshold.

When configuring the dampening command, follow these rules to set the values mentioned above:

· The ceiling is equal to 2(Max-suppress-time/Decay) × reuse-limit. It is not user configurable.

· The configured suppress limit is lower than or equal to the ceiling.

· The ceiling is lower than or equal to the maximum suppress limit supported.

Figure 1 shows the change rule of the penalty value. The lines t0 and t2 indicate the start time and end time of the suppression, respectively. The period from t0 to t2 indicates the suppression period, t0 to t1 indicates the max-suppress-time, and t1 to t2 indicates the complete decay period.

Figure 1 Change rule of the penalty value

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Restrictions and guidelines

· The dampening, link-delay, and port link-flap protect enable commands are mutually exclusive on an interface.

· The dampening command does not take effect on the administratively down events. When you execute the shutdown command, the penalty restores to 0, and the interface reports the down event to the upper-layer protocols.

· Do not enable the dampening feature on an interface with RRPP, MSTP, or Smart Link enabled.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Enable dampening on the interface.

dampening [ half-life reuse suppress max-suppress-time ]

By default, interface dampening is disabled on Ethernet interfaces.

Enabling link flapping protection on an interface

About link flapping protection

Link flapping on an interface changes network topology and increases the system overhead. For example, in an active/standby link scenario, when interface status on the active link changes between UP and DOWN, traffic switches between active and standby links. To solve this problem, configure this feature on the interface.

With this feature enabled on an interface, when the interface goes down, the system enables link flapping detection. During the link flapping detection interval, if the number of detected flaps reaches or exceeds the link flapping detection threshold, the system shuts down the interface.

Restrictions and guidelines

This feature takes effect only if it is configured in both the system view and interface view.

The dampening, link-delay, and port link-flap protect enable commands are mutually exclusive on an Ethernet interface.

To bring up an interface that has been shut down by link flapping protection, execute the undo shutdown command.

In the display interface command output, the Link-Flap DOWN value of the Current state field indicates that the interface has been shut down by link flapping protection.

Procedure

1. Enter system view.

system-view

2. Enable link flapping protection on all interfaces.

link-flap protect enable

By default, link flapping protection is disabled on all interfaces.

3. Enter Ethernet interface view.

interface interface-type interface-number

4. Enable link flapping protection on the Ethernet interface.

port link-flap protect enable [ interval interval | threshold threshold ] *

By default, link flapping protection is disabled on an Ethernet interface.

Configuring FEC

About this task

The forward error correction (FEC) feature corrects packet errors to improve transmission quality. It attaches correction information to a packet at the sending end, and corrects error codes generated during transmission at the receiving end based on the correction information. You can set the FEC mode as needed.

Feature and software compatibility

This feature is supported only in R2719 and later.

Restrictions and guidelines

This feature is supported only on 25-GE interfaces and 100-GE interfaces.

Make sure you set the same FEC mode for both interfaces of a link.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Set the FEC mode of the Ethernet interface.

port fec mode { auto | base-r | none | rs-fec }

The default FEC mode of an Ethernet interface is RS-FEC.

Configuring storm suppression

About 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.

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."

· The configured suppression threshold value in pps or kbps might be converted into a multiple of the step value supported by the chip. As a result, the effective suppression threshold might be different from the configured one. For information about the suppression threshold that takes effect, see the prompt on the device.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

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 generic flow control on an Ethernet interface

About generic flow control

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.

Restrictions and guidelines

The generic flow control and PFC features are mutually exclusive.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

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.

Configuring PFC on an Ethernet interface

About PFC

When congestion occurs in the network, the local device notifies the peer to stop sending packets carrying the specified 802.1p priority if all of the following conditions exist:

· Both the local end and the remote end have priority-based flow control (PFC) enabled.

· Both the local end and the remote end have the priority-flow-control no-drop dot1p command configured.

· The specified 802.1p priority is in the 802.1p priority list specified by the dot1p-list argument.

· The local end receives a packet carrying the specified 802.1p priority.

The state of the PFC feature is determined by the PFC configuration on the local end and on the peer end. In Table 1:

· The first row lists the PFC configuration on the local interface.

· The first column lists the PFC configuration on the peer.

· The Enabled and Disabled fields in other cells are possible negotiation results.

Make sure all interfaces that a data flow passes through have the same PFC configuration.

Table 1 PFC configurations and negotiation results

Local (right) Peer (below)	enable	auto	Default
enable	Enabled	Enabled.	Disabled
auto	Enabled	· Enabled if negotiation succeeds. · Disabled if negotiation fails.	Disabled
Default	Disabled	Disabled.	Disabled

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Restrictions and guidelines

· For IRF and other protocols to operate correctly, as a best practice, do not enable PFC for 802.1p priorities 0, 6, and 7.

· To perform PFC in an overlay network, execute the qos trust tunnel-dot1p command. For information about the overlay network, see VXLAN Configuration Guide. For information about the qos trust tunnel-dot1p command, see ACL and QoS Command Reference.

· To avoid packet loss, apply the same PFC configuration to all interfaces that the packets pass through.

· If you do not enable PFC on an interface, the interface can receive but cannot process PFC pause frames. To make PFC take effect, you must enable PFC on both ends.

The PFC and generic flow control features are mutually exclusive.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Enable PFC in auto mode or forcibly on the Ethernet interface.

priority-flow-control { auto | enable }

By default, PFC is disabled.

4. Enable PFC for 802.1p priorities.

priority-flow-control no-drop dot1p dot1p-list

By default, PFC is disabled for all 802.1p priorities.

Setting PFC thresholds

About PFC thresholds

The storage spaces for an interface include the following types:

· Headroom storage space.

· Shared storage space.

· Guaranteed storage space.

Setting PFC thresholds enables flexible control over PFC and can make good use of the storage spaces. The device supports the following PFC thresholds:

· Headroom buffer threshold—Maximum number of cell resources that can be used by packets with a specific 802.1p priority value in a headroom storage space. An interface drops received packets once this threshold is reached.

· Back pressure frame triggering threshold—Maximum number of cell resources that can be used by packets with a specific 802.1p priority value in a shared storage space. PFC is triggered once this threshold is reached. The back pressure frame triggering threshold includes the following types:

¡ Dynamic back pressure frame triggering threshold—Maximum cell resources set in percentage.

¡ Static back pressure frame triggering threshold—Maximum cell resources set in an absolute value.

· Back pressure frame stopping threshold—Maximum number of cell resources that are used by packets with a specific 802.1p priority value. When this threshold is reached after PFC is triggered, PFC will be stopped.

· PFC reserved threshold—Number of cell resources reserved for packets with a specific 802.1p priority value in a guaranteed storage space.

Restrictions and guidelines

WARNING!

After PFC is enabled for 802.1p priorities, the PFC thresholds use the default values, which are adequate in typical network environments. As a practice, change the thresholds only when necessary.

Only H3C S12500X-AF H cards support this feature.

You must enable PFC for 802.1p priorities before setting the PFC thresholds.

If you cancel PFC threshold settings on an interface, the PFC thresholds are restored to the state when only the priority-flow-control no-drop dot1p command is executed.

The dynamic back pressure frame triggering threshold and the static back pressure frame triggering threshold are exclusive. If you set one of the thresholds on an interface of a chip, you cannot set the other threshold on other interfaces of the same chip.

Setting the dynamic back pressure frame triggering threshold and enabling PFC for 802.1p priorities are exclusive. If you configure one of the features on an interface of a chip, you cannot configure the other feature on other interfaces of the same chip.

This feature does not support preprovisioning. For more information about preprovisioning, see Fundamentals Configuration Guide.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Enable PFC for 802.1p priorities.

priority-flow-control no-drop dot1p dot1p-list

By default, PFC is disabled for all 802.1p priorities.

4. Set the headroom buffer threshold.

priority-flow-control dot1p dot1p headroom headroom-number

By default, the headroom buffer threshold is 2000.

5. Set the back pressure frame triggering threshold. Choose one threshold as needed:

¡ Set the dynamic back pressure frame triggering threshold.

priority-flow-control dot1p dot1p ingress-buffer dynamic ratio

By default, no dynamic back pressure frame triggering thresholds are set.

¡ Set the static back pressure frame triggering threshold.

priority-flow-control dot1p dot1p ingress-buffer static threshold

By default, no static back pressure frame triggering thresholds are set.

6. Set the back pressure frame stopping threshold.

priority-flow-control dot1p dot1p ingress-threshold-offset offset-number

By default, no back pressure frame stopping thresholds are set.

7. Set the PFC reserved threshold.

priority-flow-control dot1p dot1p reserved-buffer reserved-number

By default, the PFC reserved threshold is 15.

Enabling energy saving features on an Ethernet interface

About energy saving features 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.

Restrictions and guidelines

Fiber ports do not support this feature.

This feature is available only in R2712 and later versions.

Configuring EEE on an Ethernet interface

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Enable EEE on the Ethernet interface.

eee enable

By default, EEE is disabled on an Ethernet interface.

Setting the statistics polling interval

About statistics polling interval

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

Setting the statistics polling interval in Ethernet interface view

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Set the statistics polling interval for the Ethernet interface.

flow-interval interval

By default, the statistics polling interval is 300 seconds.

Enabling loopback testing on an Ethernet interface

About loopback testing

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.

Restrictions and guidelines

· After you enable this feature on an Ethernet interface, the interface does not forward data traffic.

· The shutdown, port up-mode, and loopback commands are mutually exclusive.

· After you enable this feature on an Ethernet interface, the Ethernet interface switches to full duplex mode. After you disable this feature, the Ethernet interface restores to its duplex setting.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Enable loopback testing.

loopback { external | internal }

Configuring interface alarm functions

About this task

With the interface alarm functions enabled, when the number of error packets on an interface in normal state within the specified interval exceeds the upper threshold, the interface generates an upper threshold exceeding alarm and enters the alarm state. When the number of error packets on an interface in the alarm state within the specified interval drops below the lower threshold, the interface generates a recovery alarm and restores to the normal state.

Feature and software compatibility

This feature is supported only in R2719 and later.

Restrictions and guidelines

You can configure the interface alarm parameters in system view and interface view.

· The configuration in system view takes effect on all interfaces of the specified slot. The configuration in interface view takes effect only on the current interface.

· For an interface, the configuration in interface view takes priority, and the configuration in system view is used only when no configuration is made in interface view.

An interface that is shut down because of error packet alarms cannot automatically recover. To bring up the interface, execute the undo shutdown command on the interface.

If you specify the shutdown keyword for an alarm after the corresponding upper threshold is exceeded, the interface is not shut down immediately. The interface is shut down when the corresponding upper threshold is exceeded again after the previous alarm is cleared.

Enabling interface alarm functions

1. Enter system view.

system-view

2. Enable alarm functions for the interface monitoring module.

snmp-agent trap enable ifmonitor [ crc-error | input-error | input-usage | output-error | output-usage ] *

By default, all alarm functions are enabled for interfaces.

Configuring CRC error packet parameters

1. Enter system view.

system-view

2. Configure global CRC error packet alarm parameters.

In standalone mode:

ifmonitor crc-error slot slot-number high-threshold high-value low-threshold low-value interval interval [ shutdown ]

In IRF mode:

ifmonitor crc-error chassis chassis-number slot slot-number high-threshold high-value low-threshold low-value interval interval [ shutdown ]

By default, the upper threshold is 1000, the lower threshold is 100, and the statistics collection and comparison interval is 10 seconds for CRC error packets.

3. Enter Ethernet interface view.

interface interface-type interface-number

4. Configure CRC error packet alarm parameters for the interface.

port ifmonitor crc-error [ ratio ] high-threshold high-value low-threshold low-value interval interval [ shutdown ]

By default, an interface uses the global CRC error packet alarm parameters.

Configuring input error packet alarm parameters

1. Enter system view.

system-view

2. Configure global input error packet alarm parameters.

In standalone mode:

ifmonitor input-error slot slot-number high-threshold high-value low-threshold low-value interval interval [ shutdown ]

In IRF mode:

ifmonitor input-error chassis chassis-number slot slot-number high-threshold high-value low-threshold low-value interval interval [ shutdown ]

By default, the upper threshold is 1000, the lower threshold is 100, and the statistics collection and comparison interval is 10 seconds for input error packets.

3. Enter Ethernet interface view.

interface interface-type interface-number

4. Configure input error packet alarm parameters for the interface.

port ifmonitor input-error high-threshold high-value low-threshold low-value interval interval [ shutdown ]

By default, an interface uses the global input error packet alarm parameters.

Configuring output error packet alarm parameters

1. Enter system view.

system-view

2. Configure global output error packet alarm parameters.

In standalone mode:

ifmonitor output-error slot slot-number high-threshold high-value low-threshold low-value interval interval [ shutdown ]

In IRF mode:

ifmonitor output-error chassis chassis-number slot slot-number high-threshold high-value low-threshold low-value interval interval [ shutdown ]

By default, the upper threshold is 1000, the lower threshold is 100, and the statistics collection and comparison interval is 10 seconds for output error packets.

3. Enter Ethernet interface view.

interface interface-type interface-number

4. Configure output error packet alarm parameters.

port ifmonitor output-error high-threshold high-value low-threshold low-value interval interval [ shutdown ]

By default, an interface uses the global output error packet alarm parameters.

Configuring input bandwidth usage alarm parameters

1. Enter system view.

system-view

2. Configure global input bandwidth usage alarm parameters.

In standalone mode:

ifmonitor input-usage slot slot-number high-threshold high-value low-threshold low-value

In IRF mode:

ifmonitor input-usage chassis chassis-number slot slot-number high-threshold high-value low-threshold low-value

By default, the upper threshold is 90 and the lower threshold is 80 for input bandwidth usage alarms.

3. Enter Ethernet interface view.

interface interface-type interface-number

4. Configure input bandwidth usage alarm parameters.

port ifmonitor input-usage high-threshold high-value low-threshold low-value

By default, an interface uses the global input bandwidth usage alarm parameters.

Configuring output bandwidth usage alarm parameters

1. Enter system view.

system-view

2. Configure global output bandwidth usage alarm parameters.

In standalone mode:

ifmonitor output-usage slot slot-number high-threshold high-value low-threshold low-value

In IRF mode:

ifmonitor output-usage chassis chassis-number slot slot-number high-threshold high-value low-threshold low-value

By default, the upper threshold is 90 and the lower threshold is 80 for output bandwidth usage alarms.

3. Enter Ethernet interface view.

interface interface-type interface-number

4. Configure output bandwidth usage alarm parameters.

port ifmonitor output-usage high-threshold high-value low-threshold low-value

By default, an interface uses the global output bandwidth usage alarm parameters.

Restoring the default settings for an interface

Restrictions and guidelines

CAUTION:

This feature might interrupt ongoing network services. Make sure you are fully aware of the impacts of this feature when you use it in a live network.

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This feature might fail to restore the default settings for some commands because of command dependencies or system restrictions. You can use the display this command in interface view to check for these commands and perform their undo forms or follow the command reference to restore their default settings. If your restoration attempt still fails, follow the error message to resolve the problem.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view or Ethernet subinterface view.

interface interface-type { interface-number | interface-number.subnumber }

3. Restore the default settings for the interface.

default

Configuring a Layer 2 Ethernet interface

Setting the MDIX mode of an Ethernet interface

IMPORTANT:

Fiber ports do not support the MDIX mode setting.

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About MDIX mode

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.

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Restrictions and guidelines

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.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

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.

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.

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.

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.

Procedure

1. Enter system view.

system-view

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

4. 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 } upperlimit lowerlimit

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. 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 from a value above the upper threshold.

7. 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 from a value above the upper threshold.

Changing a Layer 2 Ethernet interface to an FC interface

About changing a Layer 2 Ethernet interface to an FC interface

This feature allows you to change a Layer 2 Ethernet interface to an FC interface. Support for this feature depends on the Layer 2 Ethernet interface type and device model.

Restrictions and guidelines

After you configure this feature on a Layer 2 Ethernet interface, the system deletes the interface, creates the FC interface, and enters FC interface view. This feature does not modify the interface number.

For S12500X-AF H cards, only 10-GE Layer 2 Ethernet interfaces on an H3C LSWM124XG2QFC expansion interface card in an LSXM1TGS24QGMODHB1 card can be changed to FC interfaces.

Procedure

1. Enter system view.

system-view

2. Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

3. Change the type of the interface:

¡ Change the Layer 2 Ethernet interface to an FC interface.

port-type fc

¡ Change the FC interface back to a Layer 2 Ethernet interface.

port-type ethernet

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CAUTION:

After the type of an interface is changed, the system deletes the original interface and creates a new interface that is numbered the same as the original interface. All the other commands are restored to the default on the new interface.

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Forcibly bringing up a fiber port

About forcibly bringing up a fiber port

As shown in Figure 2, 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 physically connected. 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 forcibly brings up a fiber port, even when no fiber links or transceiver modules are present for the fiber port. When one fiber link is present and up, the fiber port can forward packets over the link unidirectionally.

Figure 2 Forcibly bring up a fiber port

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Restrictions and guidelines

· Copper ports do not support this feature.

· The port up-mode, shutdown, and loopback commands are mutually exclusive.

· A fiber port forcibly brought up stays physically up whether or not a transceiver module or a fiber link is present for the port.

Procedure

1. Enter system view.

system-view

2. Enter Ethernet interface view.

interface interface-type interface-number

3. Forcibly bring up the fiber port.

port up-mode

By default, a fiber port is not forcibly brought up, and the physical state of a fiber port depends on the physical state of the fibers.

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.

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NOTE:

Fiber ports do not support this feature.

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About testing the cable connection of an Ethernet interface

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.

Procedure

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

Configuring a Layer 3 Ethernet interface or subinterface

Setting the MTU for an Ethernet interface or subinterface

Restrictions and guidelines

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

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type { interface-number | interface-number.subnumber }

3. Set the interface MTU.

mtu size

The default setting is 1500 bytes.

Setting the MAC address of an Ethernet interface or subinterface

About Layer 3 Ethernet interface MAC address

In a network, when the Layer 3 Ethernet interfaces or subinterfaces of different devices have the same MAC address, the devices might fail to communicate correctly. To eliminate the MAC address conflicts, use the mac-address command to modify the MAC addresses of Layer 3 Ethernet interfaces or subinterfaces.

Restrictions and guidelines

When you set a MAC address, make sure the following requirements are met:

· The MAC address must have the same highest 36 bits as the base MAC address.

· The MAC address must be no lower than the base MAC address plus N (decimal). The value of N varies by device model as follows:

¡ For the S12500X-AF switch series, N is 256.

¡ For the S12500-X or S9800 switch series, N is 128.

For more information about the base MAC address, see MAC address table in Layer 2—LAN Switching Configuration Guide.

Procedure

1. Enter system view.

system-view

2. Enter interface view.

interface interface-type { interface-number | interface-number.subnumber }

3. Set the interface MAC address.

mac-address mac-address

By default, no MAC address is set for an Ethernet interface.

As a best practice, do not set a MAC address in the VRRP-reserved MAC address range for a Layer 3 Ethernet subinterface.

Display and maintenance commands

IMPORTANT:

The display interface link-info command is supported only in R2719 and later.

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 interfaces capable of being split.	(In standalone mode.) display interface split-capable [ slot slot-number ] (In IRF mode.) display interface split-capable [ chassis chassis-number slot slot-number ]
Display the Ethernet module statistics.	(In standalone mode.) display ethernet statistics slot slot-number (In IRF mode.) display ethernet statistics chassis chassis-number slot slot-number
Display the operational and status information of the specified interfaces.	display interface [ interface-type [ interface-number \| interface-number.subnumber ] ] [ brief [ description \| down ] ]
Display the status and packet statistics of interfaces.	display interface link-info [ main ]
Display information about link flapping protection on interfaces.	display link-flap protection [ interface interface-type [ interface-number ] ]
Display information about dropped packets on the specified interfaces.	display packet-drop { interface [ interface-type [ interface-number ] ] \| summary }
Display PFC information on the specified interfaces.	display priority-flow-control interface [ interface-type [ interface-number ] ]
Display information about storm control on the specified interfaces.	display storm-constrain [ broadcast \| known-unicast \| multicast \| unicast ] [ interface interface-type interface-number ]
Clear interface statistics.	reset counters interface [ interface-type [ interface-number \| interface-number.subnumber ] ]
Clear the Ethernet module statistics.	(In standalone mode.) reset ethernet statistics [ slot slot-number ] (In IRF mode.) reset ethernet statistics [ chassis chassis-number slot slot-number ]
Clear the statistics of dropped packets on the specified interfaces.	reset packet-drop interface [ interface-type [ interface-number ] ]

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03-Layer 2-LAN Switching Configuration Guide

Configuring Ethernet interfaces

About Ethernet interface

About a management interface

Procedure

Ethernet interface usage restrictions and guidelines

About 100-GE interface splitting and 10-GE breakout interface combining

Restrictions and guidelines for 100-GE interface splitting and 10-GE breakout interface combining

Splitting a 100-GE interface into four 10-GE breakout interfaces

Combining four 10-GE breakout interfaces into a 100-GE interface

About 100-GE interface splitting and 25-GE breakout interface combining

Restrictions and guidelines for 100-GE interface splitting and 25-GE breakout interface combining

Splitting a 100-GE interface into four 25-GE breakout interfaces

Combining four 25-GE breakout interfaces into a 100-GE interface

About 40-GE interface splitting and 10-GE breakout interface combining

Restrictions and guidelines for 40-GE interface splitting and 10-GE breakout interface combining

Splitting a 40-GE interface into four 10-GE breakout interfaces

Combining four 10-GE breakout interfaces into a 40-GE interface

About Ethernet interface basic settings

Restrictions and guidelines

Procedure

Restrictions and guidelines for Ethernet subinterface basic settings

Procedure

About the link mode of an Ethernet interface

Procedure

About jumbo frame

Procedure

About physical state change suppression

Restrictions and guidelines

Procedure

About dampening

Parameters

Restrictions and guidelines

Procedure

About link flapping protection

Restrictions and guidelines

Procedure

About this task

Feature and software compatibility

Restrictions and guidelines

Procedure

About storm suppression

Restrictions and guidelines

Procedure

About generic flow control

Restrictions and guidelines

Procedure

About PFC

Procedure

About PFC thresholds

Restrictions and guidelines

Procedure

Enabling energy saving features on an Ethernet interface

About energy saving features on an Ethernet interface

Restrictions and guidelines

Configuring EEE on an Ethernet interface

About statistics polling interval

Setting the statistics polling interval in Ethernet interface view

About loopback testing

Restrictions and guidelines

Procedure

About this task

Feature and software compatibility

Restrictions and guidelines

Enabling interface alarm functions

Configuring CRC error packet parameters

Configuring input error packet alarm parameters

Configuring output error packet alarm parameters

Configuring input bandwidth usage alarm parameters

Configuring output bandwidth usage alarm parameters

Setting the MDIX mode of an Ethernet interface

About MDIX mode

Restrictions and guidelines

Procedure

About storm control

Restrictions and guidelines

Procedure

Changing a Layer 2 Ethernet interface to an FC interface

Restrictions and guidelines

Procedure