Table of Contents

1 Ethernet Interface Configuration· 1-1

General Ethernet Interface Configuration· 1-1

Combo Port Configuration· 1-1

Basic Ethernet Interface Configuration· 1-2

Configuring Flow Control on an Ethernet Interface· 1-3

Configuring the Suppression Time of Physical-Link-State Change on an Ethernet Interface· 1-3

Configuring Loopback Testing on an Ethernet Interface· 1-4

Configuring the Operating Mode of an Ethernet Interface· 1-4

Configuring a Layer 2 Ethernet Port 1-5

Layer 2 Ethernet Port Configuration Task List 1-5

Configuring a MAC Address for a Layer 2 Ethernet Port or Aggregate Interface· 1-6

Configuring a Port Group· 1-6

Configuring Storm Suppression· 1-7

Setting the Interval for Collecting Layer 2 Ethernet Port Statistics· 1-8

Enabling Forwarding of Jumbo Frames· 1-8

Enabling Loopback Detection on a Layer 2 Ethernet Port 1-8

Configuring the MDI Mode for a Layer 2 Ethernet Port 1-9

Testing the Cable on a Layer 2 Ethernet Port 1-10

Configuring the Storm Constrain Function on a Layer 2 Ethernet Port 1-11

Displaying and Maintaining an Ethernet Interface· 1-12

 

When configuring Ethernet interfaces, go to these sections for information you are interested in:

l          General Ethernet Interface Configuration

l          Configuring a Layer 2 Ethernet Port

l          Displaying and Maintaining an Ethernet Interface

General Ethernet Interface Configuration

The configurations described in this chapter apply to Layer 2 and Layer 3 Ethernet interfaces

Combo Port Configuration

Introduction to Combo ports

A Combo port comprises an optical (fiber) port or an electrical (copper) port. The two ports share one forwarding interface and thus they cannot work at the same time. If the electrical port is enabled, the optical port is disabled automatically and vice versa.

For the ease of management, a Combo port can be categorized into one of the following two types:

l          Single Combo port: the two Ethernet interfaces on the device panel correspond to only one interface view, in which state switchover on the two interfaces can be realized. A single Combo port can be a Layer 2 Ethernet port or a Layer 3 Ethernet interface.

l          Double Combo port: the two Ethernet interfaces on the device panel correspond to two interface views. State switchover can be realized in user’s own interface view. A double Combo port can only be a Layer 2 Ethernet port.

 

 

Configuring Combo port state

Follow these steps to configure the state of a double Combo port:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Enable a specified double Combo port	undo shutdown	Optional By default, of the two ports in a Combo port, the one with a smaller port ID is enabled. It varies with devices as to whether the enabled port is an optical port or an electrical port.

 

 

Basic Ethernet Interface Configuration

Configuring an Ethernet interface

Three types of duplex modes are available to Ethernet interfaces:

l          Full-duplex mode (full). Interfaces operating in this mode can send and receive packets simultaneously.

l          Half-duplex mode (half). Interfaces operating in this mode can either send or receive packets at a given time.

l          Auto-negotiation mode (auto). Interfaces operating in this mode determine their duplex mode through auto-negotiation.

Similarly, if you configure the transmission rate for an Ethernet interface by using the speed command with the auto keyword specified, the transmission rate is determined through auto-negotiation too..

Follow these steps to configure an Ethernet interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Set the description string	description text	Optional By default, the description of an interface is the interface name followed by the “interface” string, Ethernet1/0/1 Interface for example.
Set the duplex mode	duplex { auto | full | half }	Optional auto by default.
Set the transmission rate	speed { 10 | 100 | 1000 | auto }	Optional auto by default..
Shut down the Ethernet interface	shutdown	Optional By default, an Ethernet interface is in up state. To bring up an Ethernet interface, use the undo shutdown command.

 

 

Configuring Flow Control on an Ethernet Interface

When flow control is enabled on both sides, if traffic congestion occurs at the ingress interface, it will send a Pause frame notifying the egress interface to temporarily suspend the sending of packets. The egress interface is expected to stop sending any new packet when it receives the Pause frame. In this way, flow control helps to avoid dropping of packets. Note that this will be possible only after flow control is enabled on both the ingress and egress interfaces.

Follow these steps to enable flow control on an Ethernet interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Enable flow control	flow-control	Required Disabled by default

 

Configuring the Suppression Time of Physical-Link-State Change on an Ethernet Interface

An Ethernet interface operates in one of the two physical link states: up or down. During the suppression time, physical-link-state changes will not be propagated to the system. Only after the suppression time has elapsed will the system be notified of the physical-link-state changes by the physical layer. This functionality reduces the extra overhead occurred due to frequent physical-link-state changes within a short period of time.

Follow these steps to configure the suppression time of physical-link-state changes on an Ethernet interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Configure the up/down suppression time of physical-link-state changes	link-delay delay-time	Required By default, the physical-link-state change suppression time is not configured.

 

Configuring Loopback Testing on an Ethernet Interface

You can enable loopback testing to check whether the Ethernet interface functions properly. Note that no data packets can be forwarded during the testing. Loopback testing falls into the following two categories:

l          Internal loopback testing, which is performed within switching chips to test the functions related to the Ethernet interfaces.

l          External loopback testing, which is used to test the hardware functions of an Ethernet interface. To perform external loopback testing on an Ethernet interface, you need to install a loopback plug on the Ethernet interface. In this case, packets sent from the interface are received by the same interface.

Follow these steps to enable Ethernet interface loopback testing:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Enable loopback testing	loopback { external | internal }	Optional Disabled by default.

 

 

Configuring the Operating Mode of an Ethernet Interface

You can configure an Ethernet interface to operate in bridge (Layer 2) or route (Layer 3) mode as needed, thus specifying how an Ethernet interface forwards traffic.

l          In bridge mode, an Ethernet interface forwards traffic based on destination MAC addresses. It forwards a packet to the corresponding egress port by looking up the MAC address table for a matched entry or submits a packet to the corresponding VLAN interface for Layer 3 forwarding. An Ethernet interface operating in bridge mode supports Layer 2 functions such as VLAN.

l          In route mode, an Ethernet interface forwards traffic based on destination IP addresses only. It forwards a packet to the corresponding egress port by looking up the IP routing table for a matched entry. An Ethernet interface operating in route mode supports Layer 3 functions such as IP address configuration.

Follow these steps to change the operating mode of an Ethernet interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Change the operating mode of an Ethernet interface	port link-mode { bridge | route }	Required

 

 

Configuring a Layer 2 Ethernet Port

Layer 2 Ethernet Port Configuration Task List

Complete these tasks to configure a Layer 2 Ethernet port operating in bridge mode:

Task	Remarks
Configuring a MAC Address for a Layer 2 Ethernet Port or Aggregate Interface	Optional Applicable to Layer 2  Ethernet ports or Layer 2 aggregate interface
Configuring a Port Group	Optional Applicable to Layer 2  Ethernet ports
Configuring Storm Suppression	Optional Applicable to Layer 2 Ethernet ports
Setting the Interval for Collecting Layer 2 Ethernet Port Statistics	Optional Applicable to Layer 2  Ethernet ports
Enabling Forwarding of Jumbo Frames	Optional Applicable to Layer 2 Ethernet ports
Enabling Loopback Detection on a Layer 2 Ethernet Port	Optional Applicable to Layer 2 Ethernet ports
Configuring the MDI Mode for a Layer 2 Ethernet Port	Optional Applicable to Layer 2 Ethernet ports
Testing the Cable on a Layer 2 Ethernet Port	Optional Applicable to Layer 2 Ethernet ports
Configuring the Storm Constrain Function on a Layer 2 Ethernet Port	Optional Applicable to Layer 2 Ethernet ports

 

Configuring a MAC Address for a Layer 2 Ethernet Port or Aggregate Interface

You can use this function to manually configure a MAC address for a Layer 2 Ethernet port or Layer 2 aggregate interface. After that, when the switch sends packets of Layer 2 protocols (including cluster, DLDP, HABP, LACP, LLDP, MSTP, NDP, NTDP, and GVRP) out this interface, it can use the MAC address of this interface as the source MAC address of these protocol packets.

Configuring a MAC address for a Layer 2 Ethernet port or aggregate interface does not affect the normal forwarding of service packets.

Follow these steps to configure a MAC Address for a layer 2 Ethernet port or aggregate interface:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Layer 2 Ethernet port or aggregate interface view	interface interface-type interface-number	—
Configure a MAC address for the current interface	mac-address mac-address	Required The default MAC address of a Layer 2 Ethernet port or aggregate interface varies with device models.

Configuring a Port Group

The devices allow you to configure some functions on multiple interfaces at a time by assigning the interfaces to a port group in addition to configuring them on a per-interface basis. This is helpful when you have to configure a feature in the same way on multiple interfaces.

A port group is created manually and the settings you made on it apply to all group member interfaces. Note that even though the settings are made on the port group, they are saved on an interface basis rather than on a port group basis. Thus, you can only view the settings in the view of each interface with the display current-configuration command or the display this command.

Follow these steps to configure a manual port group:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Create a manual port group and enter manual port group view	port-group manual port-group-name	Required
Add Layer 2 Ethernet ports to the manual port group	group-member interface-list	Required

 

Configuring Storm Suppression

You can use the storm suppression function to limit the size of a particular type of traffic (currently broadcast, multicast and unknown unicast traffic) on a per-interface basis in Layer 2 Ethernet port view or port group view.

In interface or port group view, you set the maximum broadcast, multicast or unknown unicast traffic allowed to pass through an interface or each interface in a port group. When the broadcast, multicast, or unknown unicast traffic on the interface exceeds the threshold, the system discards packets until the traffic drops below the threshold.

 

 

Follow these steps to set storm suppression ratios for one or multiple Layer 2 Ethernet ports:

To do…		Use the command…	Remarks
Enter system view		system-view	—
Enter Layer 2 Ethernet port view or port group view	Enter Layer 2 Ethernet port view	interface interface-type interface-number	Use either command. If configured in Layer 2 Ethernet port view, this feature takes effect on the current port only; if configured in port group view, this feature takes effect on all ports in the port group.
	Enter port group view	port-group manual port-group-name
Set the broadcast storm suppression ratio		broadcast-suppression ratio	Optional By default, broadcast traffic is not suppressed.
Set the multicast storm suppression ratio		multicast-suppression  ratio	Optional By default, multicast traffic is not suppressed.
Set the unknown unicast storm suppression ratio		unicast-suppression ratio	Optional By default, unknown unicast traffic is not suppressed.

 

 

Setting the Interval for Collecting Layer 2 Ethernet Port Statistics

Follow these steps to configure the interval for collecting interface statistics:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Layer 2 Ethernet port view	interface interface-type interface-number	—
Configure the interval for collecting interface statistics	flow-interval interval	Optional 300 seconds by default.

 

Enabling Forwarding of Jumbo Frames

Due to tremendous amount of traffic occurring on a Layer 2 Ethernet port, it is likely that some frames greater than the standard Ethernet frame size are received. Such frames (called jumbo frames) will be dropped. With forwarding of jumbo frames enabled, the system does not drop all the jumbo frames. Instead, it continues to process jumbo frames with a size greater than the standard Ethernet frame size and yet within the specified parameter range.

This function is configured in system view and takes effect on all the Layer 2 Ethernet interfaces on the device. With forwarding of jumbo frames enabled, a FastEthernet interface allows jumbo frames with a maximum length of 1552 bytes to pass through, while a GigabitEthernet interface allows jumbo frames with a maximum length of 10240 bytes to pass through

Follow these steps to enable the forwarding of jumbo frames:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enable the forwarding of jumbo frames	jumboframe enable	By default, the device allows jumbo frames to pass through all Ethernet ports .

 

Enabling Loopback Detection on a Layer 2 Ethernet Port

If a port receives a packet that it sent out, a loop occurs. Loops may cause broadcast storms. The purpose of loopback detection is to detect loops on an interface.

When loopback detection is enabled on a Layer 2 Ethernet port, the device periodically checks whether the ports have any external loopback. If it detects a loopback on a port, the device will set that port to be under loopback detection mode.

l          If loops are detected on an access port, the port will be blocked. Meanwhile, trap messages will be sent to the terminal, and the corresponding MAC address forwarding entries will be removed.

l          If loops are detected on a trunk port or a hybrid port, trap messages are sent to the terminal. If the loopback detection control function is also enabled on the port, the port will be blocked, trap messages will be sent to the terminal, and the corresponding MAC address forwarding entries will be removed.

Follow these steps to configure loopback detection:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enable global loopback detection	loopback-detection enable	Required Disabled by default
Configure the interval for port loopback detection	loopback-detection interval-time time	Optional 30 seconds by default
Enter Layer 2 Ethernet port view	interface interface-type interface-number	—
Enable loopback detection on a port	loopback-detection enable	Required Disabled by default
Enable loopback detection control on a trunk port or a hybrid port	loopback-detection control enable	Optional Disabled by default
Enable loopback detection in all the VLANs to which trunk or hybrid ports belong	loopback-detection per-vlan enable	Optional Enabled only in the default VLAN(s) with trunk port or hybrid ports

 

 

Configuring the MDI Mode for a Layer 2 Ethernet Port

 

 

Two types of Ethernet cables can be used to connect Ethernet devices: crossover cable and straight-through cable. To accommodate these two types of cables, a Layer 2 Ethernet port on a device can operate in one of the following three Medium Dependent Interface (MDI) modes:

l          Across mode

l          Normal mode

l          Auto mode

A Layer 2 Ethernet port is composed of eight pins. By default, each pin has its particular role. For example, pin 1 and pin 2 are used for transmitting signals; pin 3 and pin 6 are used for receiving signals. You can change the pin roles through setting the MDI mode. For a Layer 2 Ethernet port in normal mode, the pin roles are not changed. For a Layer 2 Ethernet port in across mode, pin 1 and pin 2 are used for receiving signals; pin 3 and pin 6 are used for transmitting signals. To enable normal communication, you should connect the local transmit pins to the remote receive pins. Therefore, you should configure the MDI mode depending on the cable types.

l          Normally, the auto mode is recommended. The other two modes are useful only when the device cannot determine the cable type.

l          When straight-through cables are used, the local MDI mode must be different from the remote MDI mode.

l          When crossover cables are used, the local MDI mode must be the same as the remote MDI mode, or the MDI mode of at least one end must be set to auto.

Follow these steps to configure the MDI mode for a Layer 2 Ethernet port:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Layer 2 Ethernet port view	interface interface-type interface-number	—
Configure the MDI mode for the Layer 2 Ethernet port	mdi { across | auto | normal }	Optional Defaults to auto. That is, the Layer 2 Ethernet port determines the physical pin roles (transmit or receive) through negotiation.

 

Testing the Cable on a Layer 2 Ethernet Port

 

 

Follow these steps to test the current operating state of the cable connected to a Layer 2 Ethernet port:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Layer 2 Ethernet port view	interface interface-type interface-number	—
Test the cable connected to the Layer 2 Ethernet port once	virtual-cable-test	Required

 

Configuring the Storm Constrain Function on a Layer 2 Ethernet Port

The storm constrain function suppresses packet storms in an Ethernet. With this function enabled on an interface, the system detects the unicast traffic, multicast traffic, or broadcast traffic passing through the interface periodically and takes corresponding actions (that is, blocking or shutting down the interface and sending trap messages and logs) when the traffic detected exceeds the threshold.

 

 

With the storm constrain function enabled on a Layer 2 Ethernet port, you can specify the system to act as follows when the traffic detected exceeds the threshold.

l          Blocking the interface. In this case, the interface is blocked and thus stops forwarding the traffic of this type till the traffic detected is lower than the threshold. Note that an interface blocked by the storm constrain function can still forward other types of traffic and monitor the blocked traffic.

l          Shutting down the interface. In this case, the interface is shut down and stops forwarding all types of traffic. Interfaces shut down by the storm constrain function can only be brought up by using the undo shutdown command or disabling the storm constrain function.

Follow these steps to configure the storm constrain function on a Layer 2 Ethernet port:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Set the interval for generating traffic statistics	storm-constrain interval seconds	Optional 10 seconds by default
Enter Layer 2 Ethernet port view	interface interface-type interface-number	—
Enable the storm constrain function and set the lower threshold and the upper threshold	storm-constrain { broadcast | multicast | unicast } { pps | kbps | ratio } max-pps-values min-pps-values	Required Disabled by default
Set the action to be taken when the traffic exceeds the upper threshold	storm-constrain control { block | shutdown }	Optional Disabled by default
Specify to send trap messages when the traffic detected exceeds the upper threshold or drops down below the lower threshold from a point higher than the upper threshold	storm-constrain enable trap	Optional By default, the system sends trap messages when the traffic detected exceeds the upper threshold or drops down below the lower threshold from a point higher than the upper threshold.
Specify to send log when the traffic detected exceeds the upper threshold or drops down below the lower threshold from a point higher than the upper threshold	storm-constrain enable log	Optional By default, the system sends log when the traffic detected exceeds the upper threshold or drops down below the lower threshold from a point higher than the upper threshold.

 

 

Displaying and Maintaining an Ethernet Interface

To do…	Use the command…	Remarks
Display the current state of an interface and the related information	display interface [ interface-type [ interface-number ] ]	Available in any view
Display the summary of an interface	display brief interface [ interface-type [ interface-number ] ] [ | { begin | exclude | include } regular-expression ]	Available in any view
Clear the statistics of an interface	reset counters interface [ interface-type [ interface-number | interface-number.subnumber ] ]	Available in user view
Display the Combo ports and the corresponding optical/electrical ports	display port combo	Available in any view
Display the information about a manual port group or all the port groups	display port-group manual [ all | name port-group-name ]	Available in any view
Display the information about the loopback function	display loopback-detection	Available in any view