01-Ethernet Interface Configuration
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Table of Contents
1 Ethernet Interface Configuration
General Ethernet Interface Configuration
Management Ethernet Interface Configuration
Basic Ethernet Interface Configuration
Configuring Flow Control on an Ethernet Interface
Configuring Loopback Testing on an Ethernet Interface
Enabling Auto Power Down on an Ethernet Interface
Setting the Interval for Collecting Ethernet Interface Statistics
Enabling Forwarding of Jumbo Frames
Enabling Loopback Detection on an Ethernet Interface
Configuring the MDI Mode for an Ethernet Interface
Enabling Bridging on an Ethernet Interface
Testing the Cable on an Ethernet Interface
Configuring the Storm Constrain Function on an Ethernet Interface
Displaying and Maintaining an Ethernet Interface
When configuring Ethernet interfaces, go to these sections for information you are interested in:
l General Ethernet Interface Configuration
l Displaying and Maintaining an Ethernet Interface
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.
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. |
In case of a Combo port, only one interface (either the optical port or the electrical port) is active at a time. That is, once the optical port is active, the electrical port will be inactive automatically, and vice versa.
A management Ethernet interface also uses an RJ-45 connector. It can be used to connect a background PC for software loading and system debugging, or connect to a remote device, for example, a remote network management station, for remote system management. It has the attributes of a common Ethernet interface, but because it is located on the main board, it provides much faster connection speed than a common Ethernet interface when used for operations such as software loading and network management.
Follow these steps to configure a management Ethernet interface:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
— |
|
Enter management Ethernet interface view |
interface interface-type interface-number |
— |
|
Set the description string |
description text |
Optional By default, the description M-GigabitEthernet0/0/0 Interface. |
|
Shut down the management Ethernet interface |
shutdown |
Optional By default, a management Ethernet interface is up. |
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, GigabitEthernet 1/0/1 Interface for example. |
|
Set the duplex mode |
duplex { auto | full | half } |
Optional auto by default. The optical interface of a Combo port and the electrical interface of an Ethernet port whose port rate is configured as 1000 Mbps do not support the half keyword. |
|
Set the transmission rate |
speed { 10 | 100 | 1000 | auto } |
Optional The optical interface of a Combo port does not support the 10 keyword. By default, the port speed is in the auto-negotiation mode. |
|
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. |
10-Gigabit Ethernet ports do not support the duplex command or the speed command.
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 |
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. |
l As for the internal loopback test and external loopback test, if an interface is down, only the former is available on it; if the interface is shut down, both are unavailable.
l The speed, duplex, mdi, and shutdown commands are not applicable during loopback testing.
l With the loopback testing enabled, the Ethernet interface operates in full duplex mode. With the loopback testing disabled, the original configurations will be restored.
When an Ethernet interface does not receive any packet for a certain period of time, it automatically enters the power save mode and resumes its normal state upon the arrival of a packet.
Follow these steps to enable auto power down on an Ethernet interface:
|
To do… |
Use the command… |
Remarks |
|
|
Enter system view |
system-view |
— |
|
|
Enter Ethernet interface view or port group view |
Enter Ethernet interface view |
interface interface-type interface-number |
Use either command. If configured in Ethernet interface 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 |
||
|
Enable auto power down on an Ethernet interface |
port auto-power-down |
Required Disabled by default |
|
For an S5810 series Ethernet switch, the configuration of auto power down does not take effect on GigabitEthernet 1/0/45 through GigabitEthernet 1/0/48.
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 Ethernet interfaces to the manual port group |
group-member interface-list |
Required |
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 Ethernet interface 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.
The storm suppression ratio settings configured for an Ethernet interface may become invalid if you enable the storm constrain for the interface. For information about the storm constrain function, see Configuring the Storm Constrain Function on an Ethernet Interface.
Follow these steps to set storm suppression ratios for one or multiple Ethernet interfaces:
|
To do… |
Use the command… |
Remarks |
|
|
Enter system view |
system-view |
— |
|
|
Enter Ethernet interface view or port group view |
Enter Ethernet interface view |
interface interface-type interface-number |
Use either command. If configured in Ethernet interface 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 | pps max-pps | kbps max-bps } |
Optional By default, broadcast traffic is not suppressed. |
|
|
Set the multicast storm suppression ratio |
multicast-suppression { ratio | pps max-pps | kbps max-bps } |
Optional By default, multicast traffic is not suppressed. |
|
|
Set the unknown unicast storm suppression ratio |
unicast-suppression { ratio | pps max-pps | kbps max-bps } |
Optional By default, unknown unicast traffic is not suppressed. |
|
l After you set different broadcast, multicast, and unknown unicast storm suppression ratios on a port using different suppression standards (percentage of the total bandwidth, packets per second, or kilobytes per second), the system automatically changes the suppression ratio and standard for all these three types of packets to the storm (broadcast, multicast, or unknown unicast) suppression ratio and standard last configured on the port. Therefore, you are recommended to set the same storm suppression ratio and standard for these three types of packets. .
l As for an Ethernet interface belongs to a port group, if you set a storm suppression ratio for the interface in both Ethernet interface view and port group view, the one configured the last takes effect.
Follow these steps to configure the interval for collecting interface statistics:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
— |
|
Configure the interval for collecting interface statistics |
interface interface-type interface-number |
— |
|
flow-interval interval |
Optional The default interval for collecting interface statistics is 300 seconds. |
Due to tremendous amount of traffic occurring on an Ethernet interface, 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.
In global configuration mode (system view), you can set the length of jumbo frames that can pass through the Ethernet interface.
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 |
Required By default, the device allows jumbo frames with the length of 10.240 bytes to pass through all Ethernet interfaces. |
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 an Ethernet interface, 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 Ethernet interface 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 |
l Loopback detection on a given port is enabled only after the loopback-detection enable command has been configured in both system view and the interface view of the port.
l Loopback detection on all ports will be disabled after the configuration of the undo loopback-detection enable command under system view.
10-Gigabit Ethernet ports and combo ports operating as optical interfaces do not support this function.
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, an Ethernet interface 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
An Ethernet interface 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 an Ethernet interface in normal mode, the pin roles are not changed. For an Ethernet interface 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 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 MDI mode for the Ethernet interface |
mdi { across | auto | normal } |
Optional Defaults to auto. That is, the Ethernet interface determines the physical pin roles (transmit or receive) through negotiation. |
After an Ethernet port receives a data packet, it looks up the MAC address table of the device for an entry that contains the destination MAC address of the packet. If such an entry exists but the egress interface in the entry is the receiving interface itself, the device discards this packet. However, if bridging is enabled on the receiving interface, the device does not discard the packet. Instead, it sends the packet out the receiving interface.
Follow these steps to enable bridging 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 bridging on the Ethernet interface |
port bridge enable |
Required Disabled by default. |
T10-Gigabit Ethernet ports and combo ports operating as optical interfaces do not support this function.
Follow these steps to test the current operating state of the cable connected to an Ethernet interface:
|
To do… |
Use the command… |
Remarks |
|
Enter system view |
system-view |
— |
|
Enter Ethernet interface view |
interface interface-type interface-number |
— |
|
Test the cable connected to the Ethernet interface once |
virtual-cable-test |
Required |
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.
Alternatively, you can configure the storm suppression function to control a specific type of traffic. As the function and the storm constrain function are mutually exclusive, do not enable them at the same time on an Ethernet interface. For example, with unicast storm suppression ratio set on an Ethernet interface, do not enable the storm constrain function for unicast traffic on the interface. Refer to Configuring Storm Suppression for information about the storm suppression function.
With the storm constrain function enabled on an Ethernet interface, 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 an Ethernet interface:
|
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 Ethernet interface 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. |
l For network stability sake, configure the interval for generating traffic statistics to a value that is not shorter than the default.
l The storm constrain function, after being enabled, requires a complete statistical period (specified by the storm-constrain interval command) to collect traffic data, and analyzes the data in the next period. Thus, it is normal that a period longer than one statistic period is waited for a control action to happen if you enable the function while the packet storm is present. However, the action will be taken within two periods.
l The storm constrain function is applicable to unicast packets, multicast packets, and broadcast packets; and you can specify the upper and lower threshold for any of the three types of packets.
|
To do… |
Use the command… |
Remarks |
|
Display the current state of an interface/subinterface and the related information |
display interface [ interface-type [ interface-number ] ] |
Available in any view |
|
Display the summary of an interface/subinterface |
display brief interface [ interface-type [ interface-number ] ] [ | { begin | exclude | include } regular-expression ] |
Available in any view |
|
Clear the statistics of an interface/subinterface |
reset counters interface [ interface-type [ interface-number ] ] |
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 |
|
Display the information about storm constrain |
display storm-constrain [ broadcast | multicast| unicast ] [ interface interface-type interface-number ] |
Available in any view |
