03-Layer 2—LAN Switching Configuration Guide

HomeSupportResource CenterH3C S6800[S6860][S6861] (R27xx) & S6820 (R630x) Switch Series Configuration Guide-6W10103-Layer 2—LAN Switching Configuration Guide
01-MAC address table configuration
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Contents

Configuring the MAC address table· 1

About the MAC address table· 1

How a MAC address entry is created· 1

Types of MAC address entries· 1

Restrictions: Hardware compatibility with TRILL and EVB· 2

MAC address table tasks at a glance· 2

Configuring MAC address entries· 3

About MAC address entry-based frame forwarding· 3

Restrictions and guidelines for MAC address entry configuration· 3

Prerequisites for MAC address entry configuration· 4

Adding or modifying a static or dynamic MAC address entry· 4

Adding or modifying a blackhole MAC address entry· 4

Adding or modifying a multiport unicast MAC address entry· 5

Adding or modifying a multiport unicast MAC address entry for VXLAN· 6

Setting the aging timer for dynamic MAC address entries· 6

Disabling MAC address learning· 7

About disabling MAC address learning· 7

Disabling global MAC address learning· 7

Disabling MAC address learning on an interface· 8

Disabling MAC address learning on a VLAN· 8

Setting the MAC learning limit 8

Configuring the unknown frame forwarding rule after the MAC learning limit is reached· 9

Assigning MAC learning priority to interfaces· 9

Enabling MAC address synchronization· 10

Configuring MAC address move notifications and suppression· 12

Enabling ARP fast update for MAC address moves· 13

Disabling static source check· 13

Enabling SNMP notifications for the MAC address table· 14

Display and maintenance commands for MAC address table· 15

MAC address table configuration examples· 15

Example: Configuring the MAC address table· 15

Configuring MAC Information· 17

Restrictions: Hardware compatibility with EVB· 17

About MAC Information· 17

Enabling MAC Information· 17

Configuring the MAC Information mode· 18

Setting the MAC change notification interval 18

Setting the MAC Information queue length· 18

MAC Information configuration examples· 19

Example: Configuring MAC Information· 19

 


Configuring the MAC address table

About the MAC address table

An Ethernet device uses a MAC address table to forward frames. A MAC address entry includes a destination MAC address, an outgoing interface, and a VLAN ID. When the device receives a frame, it uses the destination MAC address of the frame to look for a match in the MAC address table.

·     The device forwards the frame out of the outgoing interface in the matching entry if a match is found.

·     The device floods the frame in the VLAN of the frame if no match is found.

How a MAC address entry is created

The entries in the MAC address table include entries automatically learned by the device and entries manually added.

MAC address learning

The device can automatically populate its MAC address table by learning the source MAC addresses of incoming frames on each interface.

The device performs the following operations to learn the source MAC address of incoming packets:

1.     Checks the source MAC address (for example, MAC-SOURCE) of the frame.

2.     Looks up the source MAC address in the MAC address table.

¡     The device updates the entry if an entry is found.

¡     The device adds an entry for MAC-SOURCE and the incoming port if no entry is found.

When the device receives a frame destined for MAC-SOURCE after learning this source MAC address, the device performs the following operations:

1.     Finds the MAC-SOURCE entry in the MAC address table.

2.     Forwards the frame out of the port in the entry.

The device performs the learning process for each incoming frame with an unknown source MAC address until the table is fully populated.

Manually configuring MAC address entries

Dynamic MAC address learning does not distinguish between illegitimate and legitimate frames, which can invite security hazards. When Host A is connected to Port A, a MAC address entry will be learned for the MAC address of Host A (for example, MAC A). When an illegal user sends frames with MAC A as the source MAC address to Port B, the device performs the following operations:

1.     Learns a new MAC address entry with Port B as the outgoing interface and overwrites the old entry for MAC A.

2.     Forwards frames destined for MAC A out of Port B to the illegal user.

As a result, the illegal user obtains the data of Host A. To improve the security for Host A, manually configure a static entry to bind Host A to Port A. Then, the frames destined for Host A are always sent out of Port A. Other hosts using the forged MAC address of Host A cannot obtain the frames destined for Host A.

Types of MAC address entries

A MAC address table can contain the following types of entries:

·     Static entries—A static entry is manually added to forward frames with a specific destination MAC address out of the associated interface, and it never ages out. A static entry has higher priority than a dynamically learned one.

·     Dynamic entries—A dynamic entry can be manually configured or dynamically learned to forward frames with a specific destination MAC address out of the associated interface. A dynamic entry might age out. A manually configured dynamic entry has the same priority as a dynamically learned one.

·     Blackhole entries—A blackhole entry is manually configured and never ages out. A blackhole entry is configured for filtering out frames with a specific source or destination MAC address. For example, to block all frames destined for or sourced from a user, you can configure the MAC address of the user as a blackhole MAC address entry. A blackhole entry has higher priority than a dynamically learned one.

·     Multiport unicast entries—A multiport unicast entry is manually added to send frames with a specific unicast destination MAC address out of multiple ports, and it never ages out. A multiport unicast entry has higher priority than a dynamically learned one.

A static or blackhole MAC address entry can overwrite a dynamic MAC address entry. A dynamic MAC address entry cannot overwrite a static, blackhole, or multiport unicast MAC address entry. A static entry, a blackhole entry, and a multiport unicast entry cannot overwrite one another.

A multicast unicast MAC address entry does not affect learning the corresponding dynamic MAC address entry. For the same MAC address, a multiport unicast MAC address entry and a dynamic MAC address entry can coexist, and the multiport unicast MAC address takes priority.

This document does not cover the configuration of static multicast MAC address entries and MAC address entries in VPLS. For more information about configuring static multicast MAC address entries, see IGMP snooping in IP Multicast Configuration Guide. For more information about MAC address table configuration in VPLS, see VPLS in MPLS Configuration Guide.

Restrictions: Hardware compatibility with TRILL and EVB

The S6861 switch series and S6820 switch series do not support EVB or TRILL.

MAC address table tasks at a glance

All MAC address table configuration tasks are optional.

To configure the MAC address table, perform the following tasks:

·     Configuring MAC address entries

¡     Adding or modifying a static or dynamic MAC address entry

¡     Adding or modifying a blackhole MAC address entry

¡     Adding or modifying a multiport unicast MAC address entry

¡     Adding or modifying a multiport unicast MAC address entry for VXLAN

·     Setting the aging timer for dynamic MAC address entries

·     Configuring MAC address learning

¡     Disabling MAC address learning

¡     Setting the MAC learning limit

¡     Configuring the unknown frame forwarding rule after the MAC learning limit is reached

¡     Assigning MAC learning priority to interfaces

·     Enabling MAC address synchronization

·     Configuring MAC address move notifications and suppression

·     Enabling ARP fast update for MAC address moves

·     Disabling static source check

·     Enabling SNMP notifications for the MAC address table

Configuring MAC address entries

About MAC address entry-based frame forwarding

A frame whose source MAC address matches different types of MAC address entries is processed differently.

 

Type

Description

Static MAC address entry

Forwards the frame according to the destination MAC address regardless of whether the frame's ingress interface is the same as that in the entry.

Multiport unicast MAC address entry

·     Learns the MAC address of the frame and generates a dynamic MAC address entry, but the generated dynamic MAC address entry does not take effect.

·     Forwards the frame based on the multiport unicast MAC address entry.

Blackhole MAC address entry

Drops the frame.

Dynamic MAC address entry

·     Learns the MAC address of the frames received on a different interface from that in the entry and overwrites the original entry.

·     Forwards the frame received on the same interface as that in the entry and updates the aging timer for the entry.

 

Restrictions and guidelines for MAC address entry configuration

A manually configured dynamic MAC address entry will overwrite a learned entry that already exists with a different outgoing interface for the MAC address.

The manually configured static, blackhole, and multiport unicast MAC address entries cannot survive a reboot if you do not save the configuration. The manually configured dynamic MAC address entries are lost upon reboot whether or not you save the configuration.

You cannot configure the following addresses as static, dynamic, blackhole, or multiport unicast MAC addresses:

·     Reserved MAC addresses of the device.

·     MAC addresses of Layer 3 Ethernet interfaces or subinterfaces

·     MAC addresses of Layer 3 aggregate interfaces or subinterfaces.

For the S6820 switch series, reserved MAC addresses of the device are addresses from the bridge MAC address of the device to the bridge MAC address plus 179. For other switch series, reserved MAC addresses of the device are addresses from the bridge MAC address of the device to the bridge MAC address plus 169. For more information about bridge MAC addresses, see IRF Configuration Guide. For more information about the bridge MAC address, see IRF configuration in Virtual Technologies Configuration Guide.

Prerequisites for MAC address entry configuration

Before manually configuring a MAC address entry for an interface, make sure the VLAN in the entry has been created.

Adding or modifying a static or dynamic MAC address entry

Adding or modifying a static or dynamic MAC address entry globally

1.     Enter system view.

system-view

2.     Add or modify a static or dynamic MAC address entry.

mac-address { dynamic | static } mac-address interface interface-type interface-number vlan vlan-id

By default, no MAC address entry is configured globally.

Make sure you have assigned the interface to the VLAN.

Adding or modifying a static or dynamic MAC address entry on an interface

1.     Enter system view.

system-view

2.     Enter interface view.

¡     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

¡     Enter Layer 2 aggregate interface view.

interface bridge-aggregation interface-number

¡     Enter S-channel interface view.

interface s-channel interface-number.channel-id

¡     Enter S-channel aggregate interface view.

interface schannel-aggregation interface-number:channel-id

¡     Enter S-channel bundle interface view.

interface schannel-bundle interface-number

3.     Add or modify a static or dynamic MAC address entry.

mac-address { dynamic | static } mac-address vlan vlan-id

By default, no MAC address entry is configured on an interface.

Make sure you have assigned the interface to the VLAN.

Adding or modifying a blackhole MAC address entry

1.     Enter system view.

system-view

2.     Add or modify a blackhole MAC address entry.

mac-address blackhole mac-address vlan vlan-id

By default, no blackhole MAC address entry is configured.

Adding or modifying a multiport unicast MAC address entry

About multiport unicast MAC address entry configuration

You can configure a multiport unicast MAC address entry to associate a unicast destination MAC address with multiple ports. The frame with a destination MAC address matching the entry is sent out of multiple ports.

For example, in NLB unicast mode (see Figure 1):

·     All servers within a cluster uses the cluster's MAC address as their own address.

·     Frames destined for the cluster are forwarded to every server in the group.

In this case, you can configure a multiport unicast MAC address entry on the device connected to the server group. Then, the device forwards the frame destined for the server group to every server through all ports connected to the servers within the cluster.

Figure 1 NLB cluster

 

You can configure a multiport unicast MAC address entry globally or on an interface.

Configuring a multiport unicast MAC address entry globally

1.     Enter system view.

system-view

2.     Add or modify a multiport unicast MAC address entry.

mac-address multiport mac-address interface interface-list vlan vlan-id

By default, no multiport unicast MAC address entry is configured globally.

Make sure you have assigned the interface to the VLAN.

Configuring a multiport unicast MAC address entry on an interface

1.     Enter system view.

system-view

2.     Enter interface view.

¡     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

¡     Enter Layer 2 aggregate interface view.

interface bridge-aggregation interface-number

3.     Add the interface to a multiport unicast MAC address entry.

mac-address multiport mac-address vlan vlan-id

By default, no multiport unicast MAC address entry is configured on an interface.

Make sure you have assigned the interface to the VLAN.

Adding or modifying a multiport unicast MAC address entry for VXLAN

About VXLAN multiport unicast MAC address entries

VXLAN has local and remote MAC addresses. A local MAC address is the MAC address of a VM in the local site. A remote MAC address is the MAC address of a VM in a remote site.

To send frames destined for a local or remote MAC address out of multiple ports, configure a multiport unicast MAC address entry. For more information about VXLAN, see VXLAN Configuration Guide.

Hardware and feature compatibility

The S6820 switch series does not support this feature.

Restrictions and guidelines

Do not specify the tunnel interfaces automatically created by using ENDP or EVPN as outgoing interfaces for a remote multiport unicast MAC address entry. If you do so, the numbers of these tunnel interfaces might change during tunnel re-establishment, and the related entries cannot be restored as a result. For more information about ENDP, see VXLAN Configuration Guide. For more information about EVPN, see EVPN Configuration Guide.

In an EVPN network, you cannot configure the same multiport unicast MAC address entry on multiple leaf nodes or VTEPs. When configured with EVPN multihoming or EVPN distributed relay, a VTEP does not support synchronization of multiport unicast MAC address entries. For more information about EVPN, see EVPN Configuration Guide.

Procedure

1.     Enter system view.

system-view

2.     Add or modify a multiport unicast MAC address entry for VXLAN.

¡     Add or modify a local multiport unicast MAC address entry.

mac-address multiport mac-address { interface { interface-type interface-number service-instance instance-id }&<1-4> } vsi vsi-name

For successful configuration, make sure the specified Ethernet service instances have been mapped to the specified VSI.

¡     Add or modify a remote multiport unicast MAC address entry.

mac-address multiport mac-address { interface { tunnel tunnel-number1 [ to tunnel tunnel-number2 ] }&<1-4> } vsi vsi-name

For successful configuration, make sure the specified VXLAN tunnel interfaces have been associated with the specified VSI.

Setting the aging timer for dynamic MAC address entries

About aging timer for dynamic MAC address entries

For security and efficient use of table space, the MAC address table uses an aging timer for each dynamic MAC address entry. If a dynamic MAC address entry is not updated before the aging timer expires, the device deletes the entry. This aging mechanism ensures that the MAC address table can promptly update to accommodate latest network topology changes.

A stable network requires a longer aging interval, and an unstable network requires a shorter aging interval.

An aging interval that is too long might cause the MAC address table to retain outdated entries. As a result, the MAC address table resources might be exhausted, and the MAC address table might fail to update its entries to accommodate the latest network changes.

An interval that is too short might result in removal of valid entries, which would cause unnecessary floods and possibly affect the device performance.

To reduce floods on a stable network, set a long aging timer or disable the timer to prevent dynamic entries from unnecessarily aging out. Reducing floods improves the network performance. Reducing flooding also improves the security because it reduces the chances for a data frame to reach unintended destinations.

Procedure

1.     Enter system view.

system-view

2.     Set the aging timer for dynamic MAC address entries.

mac-address timer { aging seconds | no-aging }

The default setting is 300 seconds.

Disabling MAC address learning

About disabling MAC address learning

MAC address learning is enabled by default. To prevent the MAC address table from being saturated when the device is experiencing attacks, disable MAC address learning. For example, you can disable MAC address learning to prevent the device from being attacked by a large amount of frames with different source MAC addresses.

After MAC address learning is disabled, the device immediately deletes existing dynamic MAC address entries.

Disabling global MAC address learning

Restrictions and guidelines

After you disable global MAC address learning, the device cannot learn MAC addresses on any interfaces.

Global MAC address learning does not take effect on a TRILL network, S-channel, VPLS VSI, EVB VSI, or VXLAN VSI. For information about TRILL, see TRILL Configuration Guide. For information about VPLS VSIs, see MPLS Configuration Guide. For information about S-channels and EVB VSIs, see EVB Configuration Guide. For information about VXLAN VSIs, see VXLAN Configuration Guide.

Procedure

1.     Enter system view.

system-view

2.     Disable global MAC address learning.

undo mac-address mac-learning enable

By default, global MAC address learning is enabled.

Disabling MAC address learning on an interface

About disabling MAC address learning on an interface

When global MAC address learning is enabled, you can disable MAC address learning on a single interface.

Procedure

1.     Enter system view.

system-view

2.     Enter interface view.

¡     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

¡     Enter Layer 2 aggregate interface view.

interface bridge-aggregation interface-number

¡     Enter S-channel interface view.

interface s-channel interface-number.channel-id

¡     Enter S-channel aggregate interface view.

interface schannel-aggregation interface-number:channel-id

¡     Enter S-channel bundle interface view.

interface schannel-bundle interface-number

3.     Disable MAC address learning on the interface.

undo mac-address mac-learning enable

By default, MAC address learning is enabled on an interface.

Disabling MAC address learning on a VLAN

About disabling MAC address learning on a VLAN

When global MAC address learning is enabled, you can disable MAC address learning on a per-VLAN basis.

Procedure

1.     Enter system view.

system-view

2.     Enter VLAN view.

vlan vlan-id

3.     Disable MAC address learning on the VLAN.

undo mac-address mac-learning enable

By default, MAC address learning on the VLAN is enabled.

Setting the MAC learning limit

About interface-based MAC learning limit

This feature limits the MAC address table size. A large MAC address table will degrade forwarding performance.

Restrictions and guidelines

You cannot both set the MAC learning limit and configure VLAN mapping on an interface.

The MAC learning limit does not control the number of MAC addresses learned in voice VLANs. For more information, see "Configuring voice VLANs."

Procedure

1.     Enter system view.

system-view

2.     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

3.     Set the MAC learning limit on the interface.

mac-address max-mac-count count

By default, no MAC learning limit is configured on a port.

Configuring the unknown frame forwarding rule after the MAC learning limit is reached

About unknown frame forwarding rule configuration

In this document, unknown frames refer to frames whose source MAC addresses are not in the MAC address table.

You can enable or disable forwarding of unknown frames after the MAC learning limit is reached.

Procedure

1.     Enter system view.

system-view

2.     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

3.     Configure the device to forward unknown frames received on the interface after the MAC learning limit on the interface is reached.

mac-address max-mac-count enable-forwarding

By default, the device can forward unknown frames received on an interface after the MAC learning limit on the interface is reached.

Assigning MAC learning priority to interfaces

About MAC learning priority mechanism

The MAC learning priority mechanism assigns either low priority or high priority to an interface. An interface with high priority can learn MAC addresses as usual. However, an interface with low priority is not allowed to learn MAC addresses already learned on a high-priority interface.

The MAC learning priority mechanism can help defend your network against MAC address spoofing attacks. In a network that performs MAC-based forwarding, an upper layer device MAC address might be learned by a downlink interface because of a loop or attack to the downlink interface. To avoid this issue, perform the following tasks:

·     Assign high MAC learning priority to an uplink interface.

·     Assign low MAC learning priority to a downlink interface.

Procedure

1.     Enter system view.

system-view

2.     Enter interface view.

¡     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

¡     Enter Layer 2 aggregate interface view.

interface bridge-aggregation interface-number

¡     Enter S-channel interface view.

interface s-channel interface-number.channel-id

¡     Enter S-channel aggregate interface view.

interface schannel-aggregation interface-number:channel-id

¡     Enter S-channel bundle interface view.

interface schannel-bundle interface-number

3.     Assign MAC learning priority to the interface.

mac-address mac-learning priority { high | low }

By default, low MAC learning priority is used.

Enabling MAC address synchronization

About MAC address synchronization

To avoid unnecessary floods and improve forwarding speed, make sure all member devices have the same MAC address table. After you enable MAC address synchronization, each member device advertises learned MAC address entries to other member devices.

As shown in Figure 2:

·     Device A and Device B form an IRF fabric enabled with MAC address synchronization.

·     Device A and Device B connect to AP C and AP D, respectively.

When Client A associates with AP C, Device A learns a MAC address entry for Client A and advertises it to Device B.

Figure 2 MAC address tables of devices when Client A accesses AP C

 

When Client A roams to AP D, Device B learns a MAC address entry for Client A. Device B advertises it to Device A to ensure service continuity for Client A, as shown in Figure 3.

Figure 3 MAC address tables of devices when Client A roams to AP D

 

Procedure

1.     Enter system view.

system-view

2.     Enable MAC address synchronization.

mac-address mac-roaming enable

By default, MAC address synchronization is disabled.

Configuring MAC address move notifications and suppression

About MAC address move notifications and suppression

The outgoing interface for a MAC address entry learned on interface A is changed to interface B when the following conditions exist:

·     Interface B receives a packet with the MAC address as the source MAC address.

·     Interface B belongs to the same VLAN as interface A.

In this case, the MAC address is moved from interface A to interface B, and a MAC address move occurs.

The MAC address move notifications feature enables the device to output MAC address move logs when MAC address moves are detected.

If a MAC address is continuously moved between the two interfaces, Layer 2 loops might occur. To detect and locate loops, you can view the MAC address move information. To display the MAC address move records after the device is started, use the display mac-address mac-move command.

If the system detects that MAC address moves occur frequently on an interface, you can configure MAC address move suppression to shut the interface down. The interface automatically goes up after a suppression interval. Or, you can manually bring up the interface.

Restrictions and guidelines

After you configure MAC address move notifications, the system sends only log messages to the information center module. If the device is also configured with the snmp-agent trap enable mac-address command, the system also sends SNMP notifications to the SNMP module.

Procedure

1.     Enter system view.

system-view

2.     Enable MAC address move notifications and optionally specify a MAC move detection interval.

mac-address notification mac-move [ interval interval ]

By default, MAC address move notifications are disabled.

3.     (Optional.) Set MAC address move suppression parameters.

mac-address notification mac-move suppression { interval interval | threshold threshold }

By default, the suppression interval is 30 seconds, and the suppression threshold is 3.

For the MAC address move suppression parameters to take effect, enable the MAC address move suppression on a port.

4.     Enter interface view.

¡     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

¡     Enter Layer 2 aggregate interface view.

interface bridge-aggregation interface-number

5.     Enable MAC address move suppression.

mac-address notification mac-move suppression

By default, MAC address move suppression is disabled.

Enabling ARP fast update for MAC address moves

About ARP fast update for MAC address moves

ARP fast update for MAC address moves allows the device to update an ARP entry immediately after the outgoing interface for a MAC address changes. This feature ensures data connection without interruption.

As shown in Figure 4, a mobile user laptop accesses the network by connecting to AP 1 or AP 2. When the AP to which the user connects changes, the device updates the ARP entry for the user immediately after it detects a MAC address move.

Figure 4 ARP fast update application scenario

Procedure

1.     Enter system view.

system-view

2.     Enable ARP fast update for MAC address moves.

mac-address mac-move fast-update

By default, ARP fast update for MAC address moves is disabled.

Disabling static source check

About static source check

By default, the static source check feature is enabled on an interface. The check identifies whether a received frame meets the following conditions:

·     The source MAC address of the frame matches a static MAC address entry.

·     The incoming interface of the frame is different from the outgoing interface in the entry.

If the frame meets both conditions, the device drops the frame.

When this feature is disabled, the device does not perform the check for a received frame. It can forward the frame whether or not the frame meets the conditions.

Restrictions and guidelines

To correctly forward traffic sourced from the MAC address of a VLAN interface, you must disable the static source check feature on the Layer 2 interfaces in the VLAN.

Procedure

1.     Enter system view.

system-view

2.     Enter interface view.

¡     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

¡     Enter Layer 2 aggregate interface view.

interface bridge-aggregation interface-number

¡     Enter Layer 3 Ethernet interface view.

interface interface-type interface-number

¡     Enter Layer 3 aggregate interface/subinterface view.

interface route-aggregation { interface-number | interface-number.subnumber }

¡     Enter IRF physical interface view.

interface interface-type interface-number

3.     Disable the static source check feature.

undo mac-address static source-check enable

By default, the static source check feature is enabled.

Enabling SNMP notifications for the MAC address table

About SNMP notifications for the MAC address table

To report critical MAC address move events to an NMS, enable SNMP notifications for the MAC address table. For MAC address move event notifications to be sent correctly, you must also configure SNMP on the device.

When SNMP notifications are disabled for the MAC address table, the device sends the generated logs to the information center. To display the logs, configure the log destination and output rule configuration in the information center.

For more information about SNMP and information center configuration, see the network management and monitoring configuration guide for the device.

Procedure

1.     Enter system view.

system-view

2.     Enable SNMP notifications for the MAC address table.

snmp-agent trap enable mac-address [ mac-move ]

By default, SNMP notifications are enabled for the MAC address table.

When SNMP notifications are disabled for the MAC address table, syslog messages are sent to notify important events on the MAC address table module.

Display and maintenance commands for MAC address table

Execute display commands in any view.

 

Task

Command

Display MAC address table information.

display mac-address [ mac-address [ vlan vlan-id ] | [ [ dynamic | static ] [ interface interface-type interface-number ] | blackhole | multiport ] [ vlan vlan-id ] [ count ] | nickname nickname ]

Display the aging timer for dynamic MAC address entries.

display mac-address aging-time

Display the system or interface MAC address learning state.

display mac-address mac-learning [ interface interface-type interface-number ]

Display the MAC address move records.

display mac-address mac-move [ slot slot-number]

Display MAC address statistics.

display mac-address statistics

 

MAC address table configuration examples

Example: Configuring the MAC address table

Network configuration

As shown in Figure 5:

·     Host A at MAC address 000f-e235-dc71 is connected to Ten-GigabitEthernet 1/0/1 of Device and belongs to VLAN 1.

·     Host B at MAC address 000f-e235-abcd, which behaved suspiciously on the network, also belongs to VLAN 1.

Configure the MAC address table as follows:

·     To prevent MAC address spoofing, add a static entry for Host A in the MAC address table of Device.

·     To drop all frames destined for Host B, add a blackhole MAC address entry for Host B.

·     Set the aging timer to 500 seconds for dynamic MAC address entries.

Figure 5 Network diagram

Procedure

# Add a static MAC address entry for MAC address 000f-e235-dc71 on Ten-GigabitEthernet 1/0/1 that belongs to VLAN 1.

<Device> system-view

[Device] mac-address static 000f-e235-dc71 interface ten-gigabitethernet 1/0/1 vlan 1

# Add a blackhole MAC address entry for MAC address 000f-e235-abcd that belongs to VLAN 1.

[Device] mac-address blackhole 000f-e235-abcd vlan 1

# Set the aging timer to 500 seconds for dynamic MAC address entries.

[Device] mac-address timer aging 500

Verifying the configuration

# Display the static MAC address entries for Ten-GigabitEthernet 1/0/1.

[Device] display mac-address static interface ten-gigabitethernet 1/0/1

MAC Address      VLAN ID    State            Port/Nickname            Aging

000f-e235-dc71   1          Static           XGE1/0/1                 N

# Display the blackhole MAC address entries.

[Device] display mac-address blackhole

MAC Address      VLAN ID    State            Port/Nickname            Aging

000f-e235-abcd   1          Blackhole        N/A                      N

# Display the aging time of dynamic MAC address entries.

[Device] display mac-address aging-time

MAC address aging time: 500s.

 


Configuring MAC Information

Restrictions: Hardware compatibility with EVB

The S6861 switch series and S6820 switch series do not support EVB.

About MAC Information

The MAC Information feature can generate syslog messages or SNMP notifications when MAC address entries are learned or deleted. You can use these messages to monitor user's leaving or joining the network and analyze network traffic.

The MAC Information feature buffers the MAC change syslog messages or SNMP notifications in a queue. The device overwrites the oldest MAC address change written into the queue with the most recent MAC address change when the following conditions exist:

·     The MAC change notification interval does not expire.

·     The queue has been exhausted.

To send a syslog message or SNMP notification immediately after it is created, set the queue length to zero.

Enabling MAC Information

Restrictions and guidelines

For MAC Information to take effect, you must enable MAC Information both globally and on interfaces.

Procedure

1.     Enter system view.

system-view

2.     Enable MAC Information globally.

mac-address information enable

By default, MAC Information is globally disabled.

3.     Enter interface view.

¡     Enter Layer 2 Ethernet interface view.

interface interface-type interface-number

¡     Enter S-channel interface view.

interface s-channel interface-number.channel-id

¡     Enter S-channel aggregate interface view.

interface schannel-aggregation interface-number:channel-id

¡     Enter S-channel bundle interface view.

interface schannel-bundle interface-number

4.     Enable MAC Information on the interface.

mac-address information enable { added | deleted }

By default, MAC Information is disabled on an interface.

Configuring the MAC Information mode

About MAC Information modes

The following MAC Information modes are available for sending MAC address changes:

·     Syslog—The device sends syslog messages to notify MAC address changes. The device sends syslog messages to the information center, which then outputs them to the monitoring terminal. For more information about information center, see Network Management and Monitoring Configuration Guide.

·     Trap—The device sends SNMP notifications to notify MAC address changes. The device sends SNMP notifications to the NMS. For more information about SNMP, see Network Management and Monitoring Configuration Guide.

Procedure

1.     Enter system view.

system-view

2.     Configure the MAC Information mode.

mac-address information mode { syslog | trap }

The default setting is trap.

Setting the MAC change notification interval

About the MAC change notification interval

To prevent syslog messages or SNMP notifications from being sent too frequently, you can set the MAC change notification interval to a larger value.

Procedure

1.     Enter system view.

system-view

2.     Set the MAC change notification interval.

mac-address information interval interval

The default setting is 1 second.

Setting the MAC Information queue length

About the MAC Information queue length

If the MAC Information queue length is 0, the device sends a syslog message or SNMP notification immediately after learning or deleting a MAC address.

If the MAC Information queue length is not 0, the device stores MAC changes in the queue:

·     The device overwrites the oldest MAC change written into the queue with the most recent MAC change when the following conditions exist:

¡     The MAC change notification interval does not expire.

¡     The queue has been exhausted.

·     The device sends syslog messages or SNMP notifications only if the MAC change notification interval expires.

Procedure

1.     Enter system view.

system-view

2.     Set the MAC Information queue length.

mac-address information queue-length value

The default setting is 50.

MAC Information configuration examples

Example: Configuring MAC Information

Network configuration

Enable MAC Information on Ten-GigabitEthernet 1/0/1 on Device in Figure 6 to send MAC address changes in syslog messages to the log host, Host B, through interface Ten-GigabitEthernet 1/0/2.

Figure 6 Network diagram

Restrictions and guidelines

When you edit file /etc/syslog.conf, follow these restrictions and guidelines:

·     Comments must be on a separate line and must begin with a pound sign (#).

·     No redundant spaces are allowed after the file name.

The logging facility name and the severity level specified in the /etc/syslog.conf file must be the same as those configured on the device. Otherwise, the log information might not be output correctly to the log host. The logging facility name and the severity level are configured by using the info-center loghost and info-center source commands, respectively.

Procedure

1.     Configure Device to send syslog messages to Host B:

# Enable the information center.

<Device> system-view

[Device] info-center enable

# Specify the log host 192.168.1.2/24 and specify local4 as the logging facility.

[Device] info-center loghost 192.168.1.2 facility local4

# Disable log output to the log host.

[Device] info-center source default loghost deny

To avoid output of unnecessary information, disable all modules from outputting logs to the specified destination (loghost, in this example) before you configure an output rule.

# Configure an output rule to output to the log host MAC address logs that have a severity level no lower than informational.

[Device] info-center source mac loghost level informational

2.     Configure the log host, Host B:

Configure Solaris as follows. Configure other UNIX operating systems in the same way Solaris is configured.

a.     Log in to the log host as a root user.

b.     Create a subdirectory named Device in directory /var/log/.

# mkdir /var/log/Device

c.     Create file info.log in the Device directory to save logs from Device.

# touch /var/log/Device/info.log

d.     Edit the file syslog.conf in directory /etc/ and add the following contents:

# Device configuration messages

local4.info /var/log/Device/info.log

In this configuration, local4 is the name of the logging facility that the log host uses to receive logs, and info is the informational level. The UNIX system records the log information that has a severity level no lower than informational to file /var/log/Device/info.log.

e.     Display the process ID of syslogd, end the syslogd process, and then restart syslogd using the –r option to make the new configuration take effect.

# ps -ae | grep syslogd

147

# kill -HUP 147

# syslogd -r &

The device can output MAC address logs to the log host, which stores the logs to the specified file.

3.     Enable MAC Information on Device:

# Enable MAC Information globally.

[Device] mac-address information enable

# Configure the MAC Information mode as syslog.

[Device] mac-address information mode syslog

# Enable MAC Information on Ten-GigabitEthernet 1/0/1 to enable the port to record MAC address change information when the interface performs either of the following operations:

¡     Learns a new MAC address.

¡     Deletes an existing MAC address.

[Device] interface ten-gigabitethernet 1/0/1

[Device-Ten-GigabitEthernet1/0/1] mac-address information enable added

[Device-Ten-GigabitEthernet1/0/1] mac-address information enable deleted

[Device-Ten-GigabitEthernet1/0/1] quit

# Set the MAC Information queue length to 100.

[Device] mac-address information queue-length 100

# Set the MAC change notification interval to 20 seconds.

[Device] mac-address information interval 20