Table of Contents

1 Port Basic Configuration· 1-1

Ethernet Port Configuration· 1-1

Initially Configuring a Port 1-1

Configuring Port Auto-Negotiation Speed· 1-2

Limiting Traffic on individual Ports· 1-3

Configuring Flow Control on a Port 1-3

Duplicating the Configuration of a Port to Other Ports· 1-4

Configuring Loopback Detection for an Ethernet Port 1-5

Enabling Loopback Test 1-7

Enabling the System to Test Connected Cable· 1-8

Configuring the Interval to Perform Statistical Analysis on Port Traffic· 1-8

Enabling Giant-Frame Statistics Function· 1-9

Disabling Up/Down Log Output on a Port 1-9

Configuring Storm Control on a Port 1-10

Setting the Port State Change Delay· 1-11

Displaying and Maintaining Basic Port Configuration· 1-12

Ethernet Port Configuration Example· 1-12

Troubleshooting Ethernet Port Configuration· 1-13

 

When performing basic port configuration, go to these sections for information you are interested in:

l          Ethernet Port Configuration

l          Ethernet Port Configuration Example

l          Troubleshooting Ethernet Port Configuration

 

 

Ethernet Port Configuration

Initially Configuring a Port

Follow these steps to initially configure a port:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enter Ethernet port view	interface interface-type interface-number	—
Enable the Ethernet port	undo shutdown	Optional By default, the port is enabled. Use the shutdown command to disable the port.
Set the description string for the Ethernet port	description text	Optional By default, the description string of an Ethernet port is null.
Set the duplex mode of the Ethernet port	duplex { auto | full | half }	Optional The optical interface of an SFP port does not support the half keyword By default, the duplex mode of the port is auto (auto-negotiation).
Set the speed of the Ethernet port	speed { 10 | 100 | 1000 | auto }	Optional l      By default, the speed of an Ethernet port is determined through auto-negotiation (the auto keyword). l      Use the 1000 keyword for Gigabit Ethernet ports only. l      The optical interface of an SFP port does not support the 10 or 100 keyword
Set the medium dependent interface (MDI) mode of the Ethernet port	mdi { across | auto | normal }	Optional Be default, the MDI mode of an Ethernet port is auto.
Set the maximum frame size allowed on the Ethernet port to 9,216 bytes	jumboframe enable	Optional By default, the maximum frame size allowed on an Ethernet is 9,216 bytes. To set the maximum frame size allowed on an Ethernet port to 1,536 bytes, use the undo jumboframe enable command.

 

Configuring Port Auto-Negotiation Speed

You can configure an auto-negotiation speed for a port by using the speed auto command.

Take a 10/100/1000 Mbps port as an example.

l          If you expect that 10 Mbps is the only available auto-negotiation speed of the port, you just need to configure speed auto 10.

l          If you expect that 10 Mbps and 100 Mbps are the available auto-negotiation speeds of the port, you just need to configure speed auto 10 100.

l          If you expect that 10 Mbps and 1000 Mbps are the available auto-negotiation speeds of the port, you just need to configure speed auto 10 1000.

Follow these steps to configure auto-negotiation speeds for a port:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Configure the available auto-negotiation speed(s) for the port	speed auto [ 10 | 100 | 1000 ]*	Optional l      By default, the port speed is determined through auto-negotiation. l      Use the 1000 keyword for Gigabit Ethernet ports only.

 

 

Limiting Traffic on individual Ports

By performing the following configurations, you can limit the incoming broadcast/multicast/unknown unicast traffic on individual ports. When a type of incoming traffic exceeds the threshold you set, the system drops the packets exceeding the traffic limit to reduce the traffic ratio of this type to the reasonable range, so as to keep normal network service.

Follow these steps to limit traffic on port:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Limit broadcast traffic received on each port	broadcast-suppression { ratio | pps max-pps }	Optional By default, the switch does not suppress broadcast traffic.
Enter Ethernet port view	interface interface-type interface-number	—
Limit broadcast traffic received on the current port	broadcast-suppression { ratio | pps max-pps }	Optional By default, the switch does not suppress broadcast traffic.
Limit multicast traffic received on the current port	multicast-suppression { ratio | pps max-pps }	Optional By default, the switch does not suppress multicast traffic.
Limit unknown unicast traffic received on the current port	unicast-suppression { ratio | pps max-pps }	Optional By default, the switch does not suppress unknown unicast traffic.

 

Configuring Flow Control on a Port

In situations where the receiving port is unable to process received frames, you can use the flow control function to enable the receiving port to inform the sending port to stop sending the frames for a while, thus preventing frames from being dropped.

The flow control function is implemented on a port by sending and receiving pause frames. Flow control operates in one of the following two modes on a port:

l          TxRx mode, where the port can receive and send pause frames.

l          Rx mode, where the port only can receive pause frames.

In Figure 1-1, when both Port A and Port B forward packets at 1000 Mbps, Port C is congested. To avoid packet loss, you can enable flow control on Port A, and Port B.

Figure 1-1 Configure flow control on a port

Configure flow control in TxRx mode on Port B, and flow control in Rx mode on Port A:

l          When congestions occur on Port C, Switch B buffers the frames. When the amount of the buffered frames exceeds a certain value, Switch B can realize that the traffic from Port B to Port C is too heavy and exceeds the forwarding capacity of Port C. As a result, Port B in TxRx mode sends pause frames to Port A to inform Port A to suspend packet sending.

l          Upon receiving the pause frames from Port B, Port A suspends sending packets to Port B.

l          When part of the buffered frames of Switch B are sent out Port C and the amount of the buffered frames drops to a certain level, Port B sends traffic recovery frames to Port A to inform Port A to resume frame sending. Thus, packet loss on Port C is avoided.

Follow these steps to configure flow control on a port:

To do…	Use the command…	Remarks
Enter system view	system-view	—
Enter Ethernet port view	interface interface-type interface-number	—
Configure flow control to operate in TxRx mode	flow-control	Required Use either command By default, flow control is disabled on a port.
Configure flow control to operate in Rx mode	flow-control no-pauseframe-sending

 

 

Duplicating the Configuration of a Port to Other Ports

To make other ports have the same configuration as that of a specific port, you can duplicate the configuration of a port to specific ports.

Specifically, the following types of port configuration can be duplicated from one port to other ports: VLAN configuration, protocol-based VLAN configuration, LACP configuration, QoS configuration, GARP configuration, STP configuration and initial port configuration. Refer to the command manual for the configurations that can be duplicated.

Follow these steps to duplicate the configuration of a port to specific ports:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Duplicate the configuration of a port to specific ports	copy configuration source { interface-type interface-number | aggregation-group source-agg-id } destination { interface-list [ aggregation-group destination-agg-id ] | aggregation-group destination-agg-id }	Required

 

 

Configuring Loopback Detection for an Ethernet Port

Loopback detection is used to monitor if a port of a switch is looped back.

After you enable loopback detection on Ethernet ports, the switch can monitor if an external loopback occurs on them. If there is a loopback port found, the switch will deal with the loopback port according to your configuration.

1)        If a loop is found on an access port, the system will set the port to the block state (ports in this state cannot forward data packets), send log and trap messages to the terminal, and remove the corresponding MAC forwarding entry.

l          If you have additionally enabled the loopback port auto-shutdown function on the port, the system will shut down the port, and send log and trap messages to the terminal. After the loop is removed, you need to use the undo shutdown command to bring up the port.

l          If you have not enabled the loopback port auto-shutdown function on the port, the port will automatically resume the normal forwarding state after the loop is removed.

2)        If a loop is found on a trunk or hybrid port, the system sends log and trap messages to the terminal. If you have additionally enabled the loopback port control function or the loopback port auto-shutdown function, the system will deal with the port accordingly:

l          If the loopback port control function is enabled on the port, the system will set the port to the block state (ports in this state cannot forward data packets), send log and trap messages to the terminal, and remove the corresponding MAC forwarding entry. After the loop is removed, the port will automatically resume the normal forwarding state.

l          If the loopback port auto-shutdown function is enabled on the port, the system will shut down the port and send log and trap messages to the terminal. After the loop is removed, you need to use the undo shutdown command to bring up the port.

 

 

Table 1-1 Configure loopback detection for Ethernet port(s)

Operation	Command	Remarks
Enter system view	system-view	—
Enable loopback detection globally	loopback-detection enable	Optional By default, the global loopback detection function is enabled if the device boots with the default configuration file (config.def); if the device boots with null configuration, this function is disabled.
Enable loopback detection on the specified ports in bulk	loopback-detection interface-list enable	Optional By default, the loopback detection function is enabled on ports if the device boots with the default configuration file (config.def); if the device boots with null configuration, this function is disabled.
Set the interval for performing port loopback detection	loopback-detection interval-time time	Optional The default is 30 seconds.
Enter Ethernet port view	interface interface-type interface-number	—
Enable loopback detection on a specified port	loopback-detection enable	Optional By default, the loopback detection function is enabled on ports if the device boots with the default configuration file (config.def); if the device boots with null configuration, this function is disabled.
Enable loopback port control on the trunk or hybrid port	loopback-detection control enable	Optional By default, the loopback port control function is enabled on ports if the device boots with the default configuration file (config.def); if the device boots with null configuration, this function is disabled.
Enable the loopback port auto-shutdown function	loopback-detection shutdown enable	Optional By default, the loopback port auto-shutdown function is enabled on ports if the device boots with the default configuration file (config.def); if the device boots with null configuration, this function is disabled.
Configure the system to run loopback detection on all VLANs of the current trunk or hybrid port	loopback-detection per-vlan enable	Optional By default, the system runs loopback detection only on the default VLAN of the current trunk or hybrid port.

 

 

Enabling Loopback Test

You can configure the Ethernet port to run loopback test to check if it operates normally. The port running loopback test cannot forward data packets normally. The loopback test terminates automatically after a specific period.

Follow these steps to enable loopback test:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enter Ethernet port view	interface interface-type interface-number	—
Enable loopback test	loopback { external | internal }	Required

 

 

Note that:

l          After you use the shutdown command on a port, the port cannot run loopback test.

l          You cannot use the speed, duplex, mdi and shutdown commands on the ports running loopback test.

l          Some ports do not support loopback test, and corresponding prompts will be given when you perform loopback test on them.

Enabling the System to Test Connected Cable

You can enable the system to test the cable connected to a specific port. The test result will be returned in five seconds. The system can test these attributes of the cable: Receive and transmit directions (RX and TX), short circuit/open circuit or not, the length of the faulty cable.

Follow these steps to enable the system to test connected cables:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enter Ethernet port view	interface interface-type interface-number	—
Enable the system to test connected cables	virtual-cable-test	Required

 

 

Configuring the Interval to Perform Statistical Analysis on Port Traffic

By performing the following configuration, you can set the interval to perform statistical analysis on the traffic of a port.

When you use the display interface interface-type interface-number command to display the information of a port, the system performs statistical analysis on the traffic flow passing through the port during the specified interval and displays the average rates in the interval. For example, if you set this interval to 100 seconds, the displayed information is as follows:

 Last 100 seconds input:  0 packets/sec 0 bytes/sec

 Last 100 seconds output:  0 packets/sec 0 bytes/sec

Follow these steps to set the interval to perform statistical analysis on port traffic:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enter Ethernet port view	interface interface-type interface-number	—
Set the interval to perform statistical analysis on port traffic	flow-interval interval	Optional By default, this interval is 300 seconds.

 

Enabling Giant-Frame Statistics Function

The giant-frame statistics function is used to ensure normal data transmission and to facilitate statistics and analysis of unusual traffic on the network.

Follow these steps to enable the giant-frame statistics function:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enable the giant-frame statistics function	giant-frame statistics enable	Required By default, the giant-frame statistics function is not enabled.

 

Disabling Up/Down Log Output on a Port

An Ethernet port has three physical link statuses: Up, Down, and Administratively Down. For status transition conditions, refer to the description of the display brief interface command in Basic Port Configuration Command.

When the physical link status of an Ethernet port changes between Up and Down or Up and Administratively Down, the switch will generate Up/Down log and send the log information to the terminal automatically by default. If the status of Ethernet ports in a network changes frequently, large amount of log information may be sent to the terminal, which consumes more network resources. Additionally, too frequent log information is not convenient for you to view.

You can limit the amount of the log information sent to the terminal by disabling the Up/Down log output function on some Ethernet ports selectively. For information about log output settings, refer to the Information Center module.

Disable Up/Down log output on a port

Follow these steps to disable UP/Down log output on a port:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enter Ethernet port view	interface interface-type interface-number	—
Disable a port from generating UP/Down log	undo enable log updown	Required By default, UP/Down log output is enabled.

 

Configuration examples

# In the default conditions, where UP/DOWN log output is enabled, execute the shutdown command or the undo shutdown command on Ethernet 1/0/1. The Up/Down log information for Ethernet 1/0/1 is generated and displayed on the terminal.

<Sysname> system-view

System View: return to User View with Ctrl+Z.

[Sysname] interface Ethernet 1/0/1

[Sysname-Ethernet1/0/1] shutdown

%Apr  5 07:25:37:634 2000 Sysname L2INF/5/PORT LINK STATUS CHANGE:- 1 -

 Ethernet1/0/1 is DOWN

[Sysname-Ethernet1/0/1] undo shutdown

%Apr  5 07:25:56:244 2000 Sysname L2INF/5/PORT LINK STATUS CHANGE:- 1 -

 Ethernet1/0/1 is UP

# Disable Ethernet 1/0/1 from generating Up/Down log information and execute the shutdown command or the undo shutdown command on Ethernet 1/0/1. No Up/Down log information is generated or output for Ethernet 1/0/1.

[Sysname-Ethernet1/0/1] undo enable log updown

[Sysname-Ethernet1/0/1] shutdown

[Sysname-Ethernet1/0/1] undo shutdown

Configuring Storm Control on a Port

The storm control function is used to control traffic received on an Ethernet port.

l          With traffic upper and lower thresholds specified on a port, the system periodically collects statistics about the broadcast/multicast/unicast/ traffic on the port. Once it finds that a type of traffic exceeds the specified upper threshold, it blocks this type of traffic on the port or directly shuts down the port, and outputs trap/log information according to your configuration.

l          When a type of traffic on the port falls back to the specified lower threshold, the system cancels the blocking of this type of traffic on the port or brings up the port to restore traffic forwarding for the port, and outputs log/trap information according to your configuration.

Follow these steps to configure storm control on a port:

To do...	Use the command...	Remarks
Enter system view	system-view	—
Enter Ethernet port view	interface interface-type interface-number	—
Set the upper and lower thresholds of broadcast/multicast/unicast traffic received on the port	storm-constrain { broadcast | multicast | unicast } max-packets min-packets  { pps | kbps }	Required
Set the action to be taken when a type of traffic received on the port exceeds the upper threshold.	storm-constrain control { block | shutdown }	Optional By default, no action is taken when a type of traffic reaches the upper threshold.
Enable log/trap information to be output when a type of traffic received on the port exceeds the upper threshold or falls below the lower threshold	storm-constrain enable { log | trap }	Optional Enabled by default.
Return to system view	quit	—
Set the interval at which the port collects traffic statistics	storm-constrain interval interval-value	Optional It is 10 seconds by default.

 

 

Setting the Port State Change Delay

During a short period after you connect your switch to another device, the connecting port may go up and down frequently due to hardware compatibility, resulting in service interruption.

To avoid situations like this, you may introduce a port state change delay.

 

 

Follow these steps to set the port state change delay:

To do …	Use the command …	Remarks
Enter system view	system-view	—
Enter Ethernet interface view	interface interface-type interface-number	—
Set the port state change delay	link-delay delay-time	Required No delay is introduced by default.

 

 

Displaying and Maintaining Basic Port Configuration

To do...	Use the command...	Remarks
Display port configuration information	display interface [ interface-type | interface-type interface-number ]	Available in any view
Display the enable/disable status of port loopback detection	display loopback-detection
Display brief information about port configuration	display brief interface [ interface-type [ interface-number ] ] [ | { begin | include | exclude } regular-expression ]
Display port information about a specified unit	display unit unit-id interface
Display the storm control configurations.	display storm-constrain [ interface interface-type interface-number ] [ | { begin | exclude | include } regular-expression ]
Display the statistics on the packets dropped on a port or all ports	display packet-drop { interface [ interface-type interface-number ] | summary }
Display the information about the port with the link-delay command configured	display link-delay
Clear the statistics on packets dropped on a port or all ports	reset packet-drop interface [ interface-type interface-number ]	Available in user view
Clear port statistics	reset counters interface [ interface-type | interface-type interface-number ]	Available in user view After 802.1x is enabled on a port, clearing the statistics on the port will not work.

 

Ethernet Port Configuration Example

Network requirements

l          Switch A and Switch B are connected to each other through two trunk port (Ethernet 1/0/1).

l          Configure the default VLAN ID of both Ethernet 1/0/1 to 100.

l          Allow the packets of VLAN 2, VLAN 6 through VLAN 50 and VLAN 100 to pass both Ethernet 1/0/1.

Network diagram

Figure 1-2 Network diagram for Ethernet port configuration

 

Configuration procedure

 

 

# Enter Ethernet 1/0/1 port view.

<Sysname> system-view

[Sysname] interface ethernet 1/0/1

# Set Ethernet 1/0/1 as a trunk port.

[Sysname-Ethernet1/0/1] port link-type trunk

# Allow packets of VLAN 2, VLAN 6 through VLAN 50 and VLAN 100 to pass Ethernet 1/0/1.

[Sysname-Ethernet1/0/1] port trunk permit vlan 2 6 to 50 100

# Configure the default VLAN ID of Ethernet 1/0/1 to 100.

[Sysname-Ethernet1/0/1] port trunk pvid vlan 100

Troubleshooting Ethernet Port Configuration

Symptom: Fail to configure the default VLAN ID of an Ethernet port.

Solution: Take the following steps:

l          Use the display interface or display port command to check if the port is a trunk port or a hybrid port.

l          If the port is not a trunk or hybrid port, configure it to be a trunk or hybrid port.

l          Configure the default VLAN ID of the port.