Dynamic ARP entry check disables a device from supporting dynamic ARP entries with multicast MAC addresses. The device cannot learn dynamic ARP entries containing multicast MAC addresses. You cannot manually add static ARP entries that contain multicast MAC addresses.

When dynamic ARP entry check is disabled, ARP entries containing multicast MAC addresses are supported. The device can learn dynamic ARP entries containing multicast MAC addresses obtained from the ARP packets sourced from a unicast MAC address. You can also manually add static ARP entries containing multicast MAC addresses.

Examples

# Enable dynamic ARP entry check.

<Sysname> system-view

[Sysname] arp check enable

arp check log enable

Use arp check log enable to enable the ARP logging feature.

Use undo arp check log enable to disable the ARP logging feature.

Syntax

arp check log enable

undo arp check log enable

Default

ARP logging is disabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

This feature enables a device to log ARP events when ARP cannot resolve IP addresses correctly. The log information helps administrators locate and solve problems. The device can log the following ARP events:

· On a proxy ARP-disabled interface, the target IP address of a received ARP packet is not one of the following IP addresses:

¡ The IP address of the receiving interface.

¡ The virtual IP address of the VRRP group.

· The sender IP address of a received ARP reply conflicts with one of the following IP addresses:

¡ The IP address of the receiving interface.

¡ The virtual IP address of the VRRP group.

The device sends ARP log messages to the information center. You can use the info-center source command to specify the log output rules for the information center. For more information about information center, see System Management Configuration Guide.

The device can generate a large number of ARP logs. To conserve system resources, enable ARP logging only when you are auditing or troubleshooting ARP events.

Examples

# Enable ARP logging.

<Sysname> system-view

[Sysname] arp check log enable

arp ip-unique learning enable

Use arp ip-unique learning enable to enable unique ARP entry learning for the device to learn only one ARP entry for one IP address.

Use undo arp ip-unique learning enable to disable unique ARP entry learning for IP addresses.

Syntax

arp ip-unique learning enable

undo arp ip-unique learning enable

Default

Unique ARP entry learning for IP addresses is disabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

Application scenarios

Unique ARP entry learning enables the device to learn only one ARP entry for one IP address. This feature prevents traffic loss that might occur in the IP numbered scenario because two ARP entries exist for an endpoint after it moves between interfaces of the same IP address.

After you configure one interface to borrow an IP address from another interface by using the ip address unnumbered command, the two interfaces have the same IP address. If an endpoint moves from one of the interfaces to another with its IP address unchanged, the device will learn a new ARP entry for the same IP address with a different interface than the ARP entry learned before endpoint movement. This will cause loss of packets destined for the endpoint, because the FIB entry for the endpoint is generated based on the ARP entry generated earlier for it.

Operating mechanism

With unique ARP entry learning enabled, the device deletes the existing ARP entry for an IP address when it learns a new ARP entry with a different interface than the existing entry for that IP address. This ensures that the outgoing interface in the FIB entry for the client is the one to which the endpoint is attached.

Examples

# Enable unique ARP entry learning.

<Sysname> system-view

[Sysname] arp ip-unique learning enable

Related commands

ip address unnumbered

arp ip-unnumbered learning enable

Use arp ip-unnumbered learning enable to enable an IP unnumbered interface to learn ARP entries for different subnets.

Use undo arp ip-unnumbered learning enable to disable an IP unnumbered interface from learning ARP entries for different subnets.

Syntax

arp ip-unnumbered learning enable [ source-address ip-address ]

undo arp ip-unnumbered learning enable

Default

An IP unnumbered interface cannot learn ARP entries for different subnets.

Views

Interface view

Predefined user roles

network-admin

Parameters

source-address ip-address: Specifies the sender IP address in an ARP request sent by the IP unnumbered interface. If you do not specify this option, the sender IP address in the ARP request is the borrowed IP address.

Usage guidelines

Application scenarios

An IP unnumbered interface might be unable to learn the ARP entry for the peer device if the unnumbered interface and the remote device are on different subnets. This is because some devices treat an ARP request as illegal and do not return a reply if the sender and target IP addresses in that ARP request are on different subnets.

To ensure communication between them, use this feature on the IP unnumbered interface to specify a sender IP address on the same subnet as the IP address of the peer interface on the remote device.

Restrictions and guidelines

This feature takes effect only on IP unnumbered interfaces, which are configured with the ip address unnumbered command.

To avoid ARP learning anomalies, do not execute the arp ip-unnumbered learning enable command on a non-IP-unnumbered interface.

If you disable an IP unnumbered interface from learning ARP entries for different subnets, the device deletes the existing ARP entries learned for different subnets after they age out.

Examples

# Configure HundredGigE 1/0/1 to borrow the IP address of HundredGigE 1/0/2, and enable HundredGigE 1/0/1 to learn ARP entries for different subnets.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] ip address unnumbered interface hundredgige 1/0/2

[Sysname-HundredGigE1/0/1] arp ip-unnumbered learning enable

Related commands

ip address unnumbered

arp mac-interface-consistency check enable

Use arp mac-interface-consistency check enable to enable interface consistency check between ARP and MAC address entries.

Use undo arp mac-interface-consistency check enable to disable interface consistency check between ARP and MAC address entries.

Syntax

arp mac-interface-consistency check enable

undo arp mac-interface-consistency check enable

Default

Interface consistency check between ARP and MAC address entries is disabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

In an unstable network, the receiving interface for packets from a user might change. The interface in the MAC address entry can be updated immediately while the interface in the ARP entry cannot. In this case, the packets matching the ARP entry will be sent out of an incorrect interface. To solve this problem, you can use this feature to periodically check the interface consistency between the ARP and MAC address entry for a user. If the interfaces are not the same, ARP sends ARP requests in the VLAN of the ARP entry and updates the entry with the ARP reply receiving interface.

Use the display mac-address command to display MAC address entries.

Examples

# Enable interface consistency check between ARP and MAC address entries.

<Sysname> system-view

[Sysname] arp mac-interface-consistency check enable

Related commands

display mac-address (Layer 2—LAN Switching Command Reference)

arp max-learning-num

Use arp max-learning-num to set the dynamic ARP learning limit for an interface.

Use undo arp max-learning-num to restore the default.

Syntax

arp max-learning-num max-number

undo arp max-learning-num

Default

An interface can learn a maximum of 89000 dynamic ARP entries.

Views

Layer 2 Ethernet interface view

Layer 2 aggregate interface view

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VXLAN VSI interface view

VLAN interface view

Predefined user roles

network-admin

Parameters

max-number: Specifies the maximum number of dynamic ARP entries for an interface. The value range for this argument is 0 to 89000.

Usage guidelines

An interface can dynamically learn ARP entries. To prevent an interface from holding too many ARP entries, you can set the maximum number of dynamic ARP entries that the interface can learn. When the maximum number is reached, the interface stops learning ARP entries.

When the number argument is set to 0, the interface is disabled from learning dynamic ARP entries.

Examples

# Specify VLAN-interface 40 to learn a maximum of 10 dynamic ARP entries.

<Sysname> system-view

[Sysname] interface vlan-interface 40

[Sysname-Vlan-interface40] arp max-learning-num 10

# Specify HundredGigE 1/0/1 to learn a maximum of 10 dynamic ARP entries.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] arp max-learning-num 10

# Specify Layer 2 aggregate interface Bridge-Aggregation 1 to learn a maximum of 10 dynamic ARP entries.

<Sysname> system-view

[Sysname] interface bridge-aggregation 1

[Sysname-Bridge-Aggregation1] arp max-learning-num 10

# Specify Layer 3 aggregate interface Route-Aggregation 1 to learn a maximum of 10 dynamic ARP entries.

<Sysname> system-view

[Sysname] interface route-aggregation 1

[Sysname-Route-Aggregation1] arp max-learning-num 10

arp max-learning-number

Use arp max-learning-number to set the dynamic ARP learning limit for a device.

Use undo arp max-learning-number to restore the default.

Syntax

arp max-learning-number max-number slot slot-number

undo arp max-learning-number slot slot-number

Default

The device can learn a maximum of 89000 dynamic ARP entries.

Views

System view

Predefined user roles

network-admin

Parameters

max-number: Specifies the maximum number of dynamic ARP entries for a device. The value range for this argument is 0 to 89000.

slot slot-number: Specifies a card by its slot number.

Usage guidelines

A device can dynamically learn ARP entries. To prevent a device from holding too many ARP entries, you can set the maximum number of dynamic ARP entries that the device can learn. When the maximum number is reached, the device stops learning ARP entries.

When the number argument is set to 0, the device is disabled from learning dynamic ARP entries.

Examples

# Configure the device to learn a maximum of 64 dynamic ARP entries.

<Sysname> system-view

[Sysname] arp max-learning-number 64

arp static

Use arp static to configure a static ARP entry.

Use undo arp to delete an ARP entry.

Syntax

arp static ip-address mac-address [ vlan-id interface-type interface-number | vsi-interface vsi-interface-id tunnel number vsi vsi-name | vsi-interface vsi-interface-id interface-type interface-number service-instance instance-id vsi vsi-name ] [ vpn-instance vpn-instance-name ] [ description text ]

undo arp ip-address [ vpn-instance-name ]

Default

No static ARP entries exist.

Views

System view

Predefined user roles

network-admin

Parameters

ip-address: Specifies an IP address for the static ARP entry.

mac-address: Specifies a MAC address for the static ARP entry, in the format of H-H-H.

vlan-id: Specifies the ID of a VLAN to which the static ARP entry belongs. The value range is 1 to 4094.

interface-type interface-number : Specifies an interface by its type and number.

vsi-interface vsi-interface-id: Specifies a VSI interface by its number. The value for the vsi-interface-id argument can be 1 or 17.

tunnel number: Specifies a tunnel interface by its number. The value for the number argument can be 0 to 7, 9, 11, 17, 45, 77, 79, or 100.

vsi vsi-name: Specifies a VSI by its name, a case-sensitive string of 1 to 31 characters.

service-instance instance-id: Specifies an Ethernet service instance by its ID in the range of 1 to 4096. You must specify this option if you specify a Layer 2 Ethernet interface for the preceding interface-type interface-number arguments. You cannot specify this option if you specify an interface of other types for the preceding interface-type interface-number argument.

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance to which the static ARP entry belongs. The vpn-instance-name argument represents the VPN instance name, a case-sensitive string of 1 to 31 characters. The VPN instance must already exist. To specify a static ARP entry on the public network, do not specify this option.

description text: Specifies a description of the static ARP entry. The value is a case-sensitive string of 1 to 255 characters.

Usage guidelines

A static ARP entry is manually configured and maintained. It does not age out and cannot be overwritten by any dynamic ARP entry.

Static ARP entries can be short or long.

A resolved short static ARP entry becomes unresolved upon certain events, for example, when the resolved output interface goes down, or the corresponding VLAN or VLAN interface is deleted.

Long static ARP entries are effective or ineffective. Ineffective long static ARP entries cannot be used for packet forwarding. A long static ARP entry is ineffective when any of the following conditions exists:

· The IP address in the entry conflicts with a local IP address.

· No local interface has an IP address in the same subnet as the IP address in the ARP entry.

If you specify the vlan-id interface-type interface-number argument, follow these restrictions and guidelines:

· The interface can be an Ethernet interface or an aggregate interface.

· The VLAN and VLAN interface must already exist. The specified Ethernet interface must belong to the specified VLAN.

· The IP address of the VLAN interface and the IP address specified by the ip-address argument must be on the same network.

· A long static ARP entry in a VLAN is deleted if the VLAN or VLAN interface is deleted.

On a VXLAN IP gateway that forwards traffic among VXLANs through VXLAN tunnels, a VSI interface can act as the gateway for multiple VXLANs. The VSI interface (input interface) might be connected to multiple VXLAN tunnel interfaces (output interfaces). In this case, you must specify the vsi-interface vsi-interface-id tunnel number vsi vsi-name parameters to identify a VSI interface-VSI-VXLAN tunnel interface binding. For more information about VSI interfaces, VSI, and VXLAN tunnel interfaces, see VXLAN Configuration Guide.

On a VXLAN IP gateway that forwards traffic from multiple local sites to remote sites, a VSI interface can act as the gateway for multiple local sites. The VSI interface (input interface) might be associated with multiple Ethernet services (output interfaces) on Layer 2 Ethernet interfaces through which the VSI interface connects to the local sites. In this case, you must specify the vsi-interface vsi-interface-id interface-type interface-number service-instance instance-id vsi vsi-name parameters to identify a VSI interface-Layer 2 Ethernet interface-Ethernet service instance-VSI binding. For more information about VSI interfaces, VSI, and Ethernet service instances, see VXLAN Configuration Guide.

Examples

# Configure a long static ARP entry that contains IP address 202.38.10.2, MAC address 00e0-fc01-0000, and output interface HundredGigE 1/0/1 in VLAN 10.

<Sysname> system-view

[Sysname] arp static 202.38.10.2 00e0-fc01-0000 10 hundredgige 1/0/1

# Configure a long static ARP entry that contains IP address 1.1.1.1, MAC address 00e0-fc01-0000, input interface VSI-interface 1, output interface Tunnel 1, and VSI a.

<Sysname> system-view

[Sysname] arp static 1.1.1.1 00e0-fc01-0000 vsi-interface 1 tunnel 1 vsi a

# Configure a long static ARP entry that contains IP address 1.1.1.1, MAC address 00e0-fc01-0000, input interface VSI-interface 1, output interface Ethernet instance 1 on HundredGigE 1/0/1, and VSI a.

<Sysname> system-view

[Sysname] arp static 1.1.1.1 00e0-fc01-0000 vsi-interface 1 hundredgige 1/0/1 service-in

stance 1 vsi a

Related commands

display arp

reset arp

arp timer aging

Use arp timer aging to set the aging timer for dynamic ARP entries.

Use undo arp timer aging to restore the default.

Syntax

arp timer aging { aging-minutes | second aging-seconds }

undo arp timer aging

Default

In system view, the aging timer for dynamic ARP entries is 20 minutes.

In interface view, the aging timer for dynamic ARP entries is that set in system view.

Views

System view

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VSI interface view

VLAN interface view

Predefined user roles

network-admin

Parameters

aging-minutes: Specifies the aging timer in minutes. The value range for this argument is 1 to 1440.

second aging-seconds: Specifies the aging timer in seconds. The value range for the aging-seconds argument is 5 to 86400.

Usage guidelines

Application scenarios

Each dynamic ARP entry in the ARP table has a limited lifetime, called an aging timer. The aging timer of a dynamic ARP entry is reset each time the dynamic ARP entry is updated. Dynamic ARP entries that are not updated before their aging timers expire are deleted from the ARP table.

You can set the aging timer for dynamic ARP entries to ensure that dynamic ARP entries are updated in a timely manner.

Restrictions and guidelines

You can set the aging timer for dynamic ARP entries in system view or in interface view. The aging timer set in interface view takes precedence over the aging timer set in system view.

Set the aging timer for dynamic ARP entries as needed. For example, when you configure proxy ARP, set a short aging time so that invalid dynamic ARP entries can be deleted in a timely manner.

Examples

# Set the aging timer for dynamic ARP entries to 10 minutes.

<Sysname> system-view

[Sysname] arp timer aging 10

# Set the aging timer for dynamic ARP entries to 200 seconds.

<Sysname> system-view

[Sysname] arp timer aging second 200

# Set the aging timer for dynamic ARP entries to 200 seconds on HundredGigE 1/0/1.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] arp timer aging second 200

Related commands

display arp timer aging

arp timer aging probe-count

Use arp timer aging probe-count to set the maximum number of probes for dynamic ARP entries.

Use undo arp timer aging probe-count to restore the default.

Syntax

arp timer aging probe-count count

undo arp timer aging probe-count

Default

In system view, the maximum number of probes for dynamic ARP entries is 3.

In interface view, the maximum number of probes for dynamic ARP entries is that set in system view.

Views

System view

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VSI interface view

VLAN interface view

Predefined user roles

network-admin

Parameters

count: Specifies the maximum number of probes. The value range for this argument is 0 to 10. To disable the device from probing dynamic ARP entries, set the value to 0.

Usage guidelines

Dynamic ARP entry probing prevents legal dynamic ARP entries from aging out, avoiding unnecessary ARP resolution in forwarding.

This probe feature sends ARP requests for the IP address in a dynamic ARP entry before it ages out.

· If the device receives an ARP reply before the entry aging timer expires, the device resets the aging timer.

· If the device makes the maximum number of probes without receiving a reply, the device deletes the entry when the entry aging timer expires.

You can set the maximum number of probes in system view and in interface view. The setting in interface view takes precedence over that in system view.

Examples

# Configure the device to perform a maximum of five probes for dynamic ARP entries.

<Sysname> system-view

[Sysname] arp timer aging probe-count 5

# Configure the device to perform a maximum of five probes for dynamic ARP entries on HundredGigE 1/0/1.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] arp timer aging probe-count 5

Related commands

arp timer aging

arp timer aging probe-interval

Use arp timer aging probe-interval to set the interval for probing dynamic ARP entries.

Use undo arp timer aging probe-interval to restore the default.

Syntax

arp timer aging probe-interval interval

undo arp timer aging probe-interval

Default

In system view, the probe interval is 5 seconds.

In interface view, the probe interval is that set in system view.

Views

System view

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VSI interface view

VLAN interface view

Predefined user roles

network-admin

Parameters

Interval: Specifies the probe interval, in seconds. The value rang is 1 to 60.

Usage guidelines

Dynamic ARP entry probing prevents legal dynamic ARP entries from aging out, avoiding unnecessary ARP resolution in forwarding.

Before a dynamic ARP entry ages out, the device sends ARP requests for the IP address in the ARP entry.

· If the device receives an ARP reply before a probe interval expires, the device resets the aging timer.

· If the device has not received an ARP reply when a probe interval expires, the device starts a new probe.

· If the device makes the maximum number probes without receiving an ARP reply, the device deletes the entry.

You can set the probe interval in system view and in interface view. The probe interval in interface view takes precedence over the probe interval in system view.

Examples

# Set the probe interval to 10 seconds for dynamic ARP entries.

<Sysname> system-view

[Sysname] arp timer aging probe-interval 10

# Set the probe interval to 10 seconds for dynamic ARP entries on HundredGigE 1/0/1.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] arp timer aging probe-interval 10

Related commands

arp timer aging

arp timer aging probe-count

arp user-ip-conflict record enable

Use arp user-ip-conflict record enable to enable recording user IP address conflicts.

Use undo arp user-ip-conflict record enable to disable recording user IP address conflicts.

Syntax

arp user-ip-conflict record enable

undo arp user-ip-conflict record enable

Default

Recording user IP address conflicts is disabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

This feature enables the device to detect and record user IP address conflicts. The device determines that a conflict occurs if an incoming ARP packet has the same sender IP address as an existing ARP entry but a different sender MAC address. The device generates a user IP address conflict record, logs the conflict, and sends the log to the information center. For information about the log destination and output rule configuration, see the information center in System Management Configuration Guide.

A card can generate a maximum of 10 user IP address conflict logs per second.

To display user IP address conflict records, use the display arp user-ip-conflict record command.

Examples

# Enable recording user IP address conflicts.

<Sysname> system-view

[Sysname] arp user-ip-conflict record enable

Related commands

display arp user-ip-conflict record

arp user-move record enable

Use user-move record enable to enable recording user port migrations.

Use undo arp user-move record enable to disable recording user port migrations.

Syntax

arp user-move record enable

undo arp user-move record enable

Default

Recording user port migrations is disabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

Each card can generate a maximum of 10 user port migration logs per second.

To display user port migration records, use the display arp user-move record command.

Examples

# Enable recording user port migration.

<Sysname> system-view

[Sysname] arp user-move record enable

Related commands

display arp user-move record

display arp

Use display arp to display ARP entries.

Syntax

display arp [ [ all | dynamic | static ] [ slot slot-number ] | interface interface-type interface-number ] [ count | verbose ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

all: Displays all ARP entries.

dynamic: Displays dynamic ARP entries.

static: Displays static ARP entries.

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command displays ARP entries for the active MPU.

interface interface-type interface-number: Specifies an interface by its type and number. If you do not specify an interface, this command displays ARP entries for all interfaces.

verbose: Displays detailed information about ARP entries.

Usage guidelines

This command displays information about static and dynamic ARP entries, including the IP address, MAC address, VLAN ID, output interface, entry type, and aging timer.

Examples

# Display all ARP entries.

<Sysname> display arp all

Type: S-Static D-Dynamic O-Openflow R-Rule I-Invalid

IP address MAC address VLAN/VSI name Interface Aging Type

1.1.1.1 02e0-f102-0023 1 HGE1/0/1 -- S

1.1.1.2 00e0-fc00-0001 12 HGE1/0/2 960 D

1.1.1.3 00e0-fe50-6503 vsi1 Tunnel1 960 D

# Display detailed information about all ARP entries.

<Sysname> display arp all verbose

Type: S-Static D-Dynamic O-Openflow R-Rule I-Invalid

IP address : 1.1.1.1 MAC address : 02e0-f102-0023

Type : Static Aging : --

Interface : HGE1/0/1 SVLAN/CVLAN : 1/--

VPN instance : --

Link ID : --

Service instance : --

VXLAN ID : --

VSI name : --

VSI interface : --

IP address : 1.1.1.2 MAC address : 00e0-fc00-0001

Type : Dynamic Aging : 960 seconds

Interface : HGE1/0/2 SVLAN/CVLAN : 12/--

VPN instance : --

Link ID : --

Service instance : --

VXLAN ID : --

VSI name : --

VSI interface : --

IP address : 1.1.1.3 MAC address : 00e0-fe50-6503

Type : Dynamic Aging : 960 seconds

Interface : Tunnel1 SVLAN/CVLAN : 12/--

VPN instance : --

Link ID : --

Service instance : --

VXLAN ID : --

VSI name : vsi1

VSI interface : --

# Display the number of all ARP entries.

<Sysname> display arp all count

Total number of entries : 3

Table 1 Command output

Field	Description
IP address	IP address in an ARP entry.
MAC address	MAC address in an ARP entry.
VLAN/VSI name	ID of the VLAN or name of the VSI to which an ARP entry belongs. This field displays hyphens (--) in either of the following situations: · The ARP entry is an unresolved short static ARP entry. · The output interface of the ARP entry does not belong to any SVLAN or VSI.
Interface	Output interface in an ARP entry. This field displays hyphens (--) if the ARP entry is an unresolved short static ARP entry.
Aging	Aging time for an ARP entry, in seconds. · For a static ARP entry, this field always displays hyphens (--). The static ARP entry never ages out unless you delete it manually. · For a dynamic ARP entry, this field displays hyphens (--) if the aging time is unknown.
Type	ARP entry type: · D—Dynamic. · S—Static. · O—OpenFlow. · R—Rule. · I—Invalid.
SVLAN/CVLAN	ID of the SVLAN or CVLAN to which the ARP entry belongs. This field displays hyphens (--) in either of the following situations: · The ARP entry is an unresolved short static ARP entry. · The output interface of the ARP entry does not belong to any SVLAN or CVLAN.
VPN instance	Name of VPN instance. This field displays hyphens (--) if no VPN instance is configured for the ARP entry.
Link ID	Link ID in an ARP entry. This field displays hyphens (--) if the ARP entry does not belong to any VSI.
Service instance	Ethernet service instance in an ARP entry. This field displays hyphens (--) if no Ethernet service instance is specified for the Layer 2 Ethernet interface or Layer 2 aggregate interface in the ARP entry.
VXLAN ID	VXLAN ID (also called VNI). This field displays hyphens (--) if the ARP entry does not belong to any VXLAN.
VSI name	Name of the VSI to which the ARP entry belongs. This field displays hyphens (--) if the ARP entry does not belong to a specific VSI.
VSI interface	VSI interface specified for the VSI. This field displays hyphens (--) if no VSI interface is specified for the VSI.
Total number of entries	Number of ARP entries.

‌

Related commands

arp static

reset arp

display arp entry-limit

Use display arp entry-limit to display the maximum number of ARP entries that a device supports.

Syntax

display arp entry-limit

Views

Any view

Predefined user roles

network-admin

network-operator

Examples

# Display the maximum number of ARP entries that the device supports.

<Sysname> display arp entry-limit

ARP entries: 747520

display arp ip-address

Use display arp ip-address to display the ARP entry for an IP address.

Syntax

display arp ip-address [ slot slot-number ] [ verbose ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

ip-address: Displays the ARP entry for the specified IP address.

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command displays information for the active MPU.

verbose: Displays the detailed information about the specified ARP entry.

Usage guidelines

The ARP entry information includes the IP address, MAC address, VLAN ID, output interface, entry type, and aging timer.

Examples

# Display the ARP entry for the IP address 20.1.1.1.

<Sysname> display arp 20.1.1.1

Type: S-Static D-Dynamic O-Openflow R-Rule I-Invalid

IP address MAC address VLAN/VSI name Interface Aging Type

20.1.1.1 00e0-fc00-0001 N/A -- -- S

Related commands

arp static

reset arp

display arp openflow count

Use display arp openflow count to display the number of OpenFlow ARP entries.

Syntax

display arp openflow count [ slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command displays the number of OpenFlow ARP entries for the active MPU.

Examples

# Display the number of OpenFlow ARP entries.

<Sysname> display arp openflow count

Total number of OpenFlow ARP entries: 6

display arp timer aging

Use display arp timer aging to display the aging timer of dynamic ARP entries.

Syntax

display arp timer aging

Views

Any view

Predefined user roles

network-admin

network-operator

Usage guidelines

This command always displays the aging time in seconds no matter which unit you set in the arp timer aging command.

Examples

# Display the aging timer of dynamic ARP entries.

<Sysname> display arp timer aging

Current ARP aging time is 1200 seconds

Related commands

arp timer aging

display arp usage

Use display arp usage to display ARP table usage statistics.

Syntax

display arp usage

Views

Any view

Predefined user roles

network-admin

network-operator

Usage guidelines

This command displays the maximum number of ARP entries supported on the device and history ARP table usage statistics.

You can monitor ARP table usage statistics on the device for the following purposes:

· Take action to prevent the ARP table from getting full.

· Monitor the ARP learning rate to identify presence of ARP flood attacks.

The device displays ARP table usage statistics only for the most recent hour.

Examples

# Display ARP table usage statistics.

<Sysname> display arp usage

ARP table upper limit: 65000

Time ARP entry count Usage

Current 52000 80%

1 min ago 51351 79%

2 min ago 50711 78%

3 min ago 47748 77%

…

59 min ago 13656 21%

60 min ago 13007 20%

Table 2 Command output

Field	Description
ARP table upper limit	Maximum number of ARP entries supported on the device.
Time	Time when the number of ARP entries were counted. This field displays Current if the number of ARP entries were counted just now.
ARP entry count	Number of ARP entries.
Usage	ARP table usage, which is the ratio of the real-time ARP entry count to the ARP table upper limit.

display arp user-ip-conflict record

Use display arp user-ip-conflict record to display user IP address conflict records.

Syntax

display arp user-ip-conflict record [ slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command displays user IP address conflict records for the active MPU.

Usage guidelines

Each card can save a maximum of 200 user IP address conflict records.

If the maximum number is reached, a new record will override the earliest record.

Examples

# Display all user IP address conflict records.

<Sysname> display arp user-ip-conflict record

IP address: 10.1.1.1

System time: 2018-02-02 11:22:29

Conflict count: 1

Log suppress count: 0

Old interface: HundredGigE1/0/1

New interface: HundredGigE1/0/2

Old SVLAN/CVLAN: 100/2

New SVLAN/CVLAN: 100/2

Old MAC: 00e0-ca63-8141

New MAC: 00e0-ca63-8142

IP address: 10.1.1.2

System time: 2018-02-02 10:20:30

Conflict count: 1

Log suppress count: 0

Old interface: HundredGigE1/0/1

New interface: HundredGigE1/0/2

Old SVLAN/CVLAN: 100/--

New SVLAN/CVLAN: 100/--

Old MAC: 00e0-ca63-8141

New MAC: 00e0-ca63-8142

Table 3 Command output

Field	Description
IP address	IP address of a user.
System time	Time when the user IP address conflict occurred.
Conflict count	Number of times that conflicts for the IP address.
Log suppress count	Number of times that user IP address conflict logs are suppressed.
Old interface	Output interface in the old ARP entry.
New interface	Output interface in the new ARP entry.
Old SVLAN/CVLAN	ID of the outer VLAN or inner VLAN in the old ARP entry. This field displays hyphens (--) if the ARP entry does not belong to any outer VLAN or inner VLAN.
New SVLAN/CVLAN	ID of the outer VLAN or inner VLAN in the new ARP entry. This field displays hyphens (--) if the ARP entry does not belong to any outer VLAN or inner VLAN.
Old MAC	MAC address in the old ARP entry.
New MAC	MAC address in the new ARP entry.

Related commands

arp user-ip-conflict record enable

display arp user-move record

Use display arp user-move record to display user port migration records.

Syntax

display arp user-move record [ slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command displays user port migration records for the active MPU.

Usage guidelines

Each card can save a maximum of 200 user port migration records.

When the number of user port migration records reaches the upper limit, new records will overwrite the earliest ones.

Examples

# Display all user port migration records.

<Sysname> display arp user-move record

IP address: 10.1.1.1

MAC address: 0001-0201-0e81

System time: 2018-02-02 11:22:29

Move count: 1

Log suppress count: 0

Before:

interface: HundredGigE1/0/1

SVLAN/CVLAN: 100/2

After:

interface: HundredGigE1/0/2

SVLAN/CVLAN: 100/2

IP address: 10.1.1.2

MAC address: 0001-0201-0e82

System time: 2018-02-02 10:20:30

Move count: 1

Log suppress count: 0

Before:

interface: HundredGigE1/0/1

SVLAN/CVLAN: 100/--

After:

interface: HundredGigE1/0/2

SVLAN/CVLAN: 100/--

Table 4 Command output

Field	Description
IP address	IP address of the user.
MAC address	MAC address of the user.
System time	Time when the user port migration occurred.
Move count	Number of times that user port migrated.
Log suppress count	Number of times that the generation of user port migration logs is suppressed.
Interface	Output interface in the ARP entry.
SVLAN/CVLAN	ID of the outer VLAN or inner VLAN in the ARP entry. This field displays hyphens (--) if the ARP entry does not belong to any outer VLAN or inner VLAN.

Related commands

arp user-move record enable

display arp vpn-instance

Use display arp vpn-instance to display the ARP entries for a VPN instance.

Syntax

display arp vpn-instance vpn-instance-name [ count ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. The VPN instance name cannot contain any spaces.

Usage guidelines

This command displays information about ARP entries for a VPN instance, including the IP address, MAC address, VLAN ID, output interface, entry type, and aging timer.

Examples

# Display ARP entries for VPN instance test.

<Sysname> display arp vpn-instance test

Type: S-Static D-Dynamic O-Openflow R-Rule I-Invalid

IP address MAC address VLAN/VSI name Interface Aging Type

20.1.1.1 00e0-fc00-0001 -- -- -- S

Related commands

arp static

reset arp

Use reset arp to clear ARP entries from the ARP table.

Syntax

reset arp { all | dynamic | interface interface-type interface-number | slot slot-number | static }

Views

User view

Predefined user roles

network-admin

Parameters

all: Clears all ARP entries.

dynamic: Clears all dynamic ARP entries.

static: Clears all static ARP entries.

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command clears ARP entries for the active MPU.

interface interface-type interface-number: Specifies an interface by its type and number. If you do not specify an interface, this command clears ARP entries for all interfaces.

Usage guidelines

CAUTION:

The reset arp command will clear existing ARP entries from the ARP table. It might cause that external users cannot quickly communicate with the LAN users.

Examples

# Clear all static ARP entries.

<Sysname> reset arp static

Related commands

arp static

display arp

Gratuitous ARP commands

arp ip-conflict log prompt

Use arp ip-conflict log prompt to enable IP conflict notification.

Use undo arp ip-conflict log prompt to restore the default.

Syntax

arp ip-conflict log prompt

undo arp ip-conflict log prompt

Default

IP conflict notification is disabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

By default, the device performs the following operations if it is using the sender IP address of a received ARP packet:

· Sends a gratuitous ARP request.

· Displays an error message after the device receives an ARP reply about the conflict.

You can use this command to enable the device to display error messages before sending a gratuitous ARP reply or request for conflict confirmation.

Examples

# Enable IP conflict notification on the device.

<Sysname> system-view

[Sysname] arp ip-conflict log prompt

arp send-gratuitous-arp

Use arp send-gratuitous-arp to enable periodic sending of gratuitous ARP packets on an interface.

Use undo arp send-gratuitous-arp to disable the interface from periodically sending gratuitous ARP packets.

Syntax

arp send-gratuitous-arp [ interval interval ]

undo arp send-gratuitous-arp

Default

Periodic sending of gratuitous ARP packets is disabled.

Views

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VXLAN VSI interface view

VLAN interface view

Predefined user roles

network-admin

Parameters

interval interval: Specifies the sending interval in the range of 200 to 200000 milliseconds. The default value is 2000 milliseconds.

Usage guidelines

This feature takes effect on an interface only when the interface has an IP address and the data link layer state of the interface is up.

This feature can send gratuitous ARP requests only for a VRRP virtual IP address, or the sending interface's primary IP address or manually configured secondary IP address. The primary IP address can be configured manually or automatically, whereas the secondary IP address must be configured manually.

If you change the sending interval for gratuitous ARP packets, the configuration takes effect at the next sending interval.

The sending interval for gratuitous ARP packets might be much longer than the set interval when any of the following conditions exist:

· This feature is enabled on multiple interfaces.

· Each interface is configured with multiple secondary IP addresses.

· A small sending interval is configured in the preceding cases.

Examples

# Enable HundredGigE 1/0/1 to send gratuitous ARP packets every 300 milliseconds.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] arp send-gratuitous-arp interval 300

gratuitous-arp mac-change retransmit

Use gratuitous-arp mac-change retransmit to set the times and the interval for retransmitting a gratuitous ARP packet for the device MAC address change.

Use undo gratuitous-arp mac-change retransmit to restore the default.

Syntax

gratuitous-arp mac-change retransmit times interval seconds

undo gratuitous-arp mac-change retransmit

Default

The device sends a gratuitous packet for its MAC address change once only.

Views

System view

Predefined user roles

network-admin

Parameters

times: Specifies the times of retransmitting a gratuitous packet, in the range of 1 to 10.

interval seconds: Specifies the interval for retransmitting a gratuitous packet, in the range of 1 to 10 seconds.

Usage guidelines

The device sends a gratuitous ARP packet to inform other devices of its MAC address change. However, the other devices might fail to receive the packet because the device sends the gratuitous ARP packet once only by default. Use this command to configure gratuitous ARP retransmission parameters to ensure that the other devices can receive the packet.

After you execute this command, the device will retransmit a gratuitous ARP packet for its MAC address change at the specified interval for the specified times.

Examples

# Set the times to 3 and the interval to 5 for retransmitting a gratuitous ARP packet for the device MAC address change.

<Sysname> system-view

[Sysname] gratuitous-arp mac-change retransmit 3 interval 5

gratuitous-arp-learning enable

Use gratuitous-arp-learning enable to enable learning of gratuitous ARP packets.

Use undo gratuitous-arp-learning enable to disable learning of gratuitous ARP packets.

Syntax

gratuitous-arp-learning enable

undo gratuitous-arp-learning enable

Default

Learning of gratuitous ARP packets is enabled.

Views

System view

Predefined user roles

network-admin

Usage guidelines

The learning of gratuitous ARP packets feature allows a device to maintain its ARP table by creating or updating ARP entries based on received gratuitous ARP packets.

When this feature is disabled, the device uses received gratuitous ARP packets to update existing ARP entries only. ARP entries are not created based on the received gratuitous ARP packets, which saves ARP table space.

Examples

# Enable learning of gratuitous ARP packets.

<Sysname> system-view

[Sysname] gratuitous-arp-learning enable

gratuitous-arp-sending enable

Use gratuitous-arp-sending enable to enable sending gratuitous ARP packets upon receiving ARP requests whose sender IP address is on a different subnet.

Use undo gratuitous-arp-sending enable to disable sending gratuitous ARP packets upon receiving ARP requests whose sender IP address is on a different subnet.

Syntax

gratuitous-arp-sending enable

undo gratuitous-arp-sending enable

Default

A device does not send gratuitous ARP packets when it receives ARP requests whose sender IP address is on a different subnet.

Views

System view

Predefined user roles

network-admin

Examples

# Disable a device from sending gratuitous ARP packets upon receiving ARP requests whose sender IP address is on a different subnet.

<Sysname> system-view

[Sysname] undo gratuitous-arp-sending enable

Proxy ARP commands

display local-proxy-arp

Use display local-proxy-arp to display the local proxy ARP status.

Syntax

display local-proxy-arp [ interface interface-type interface-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

interface interface-type interface-number: Specifies an interface by its type and number. If you do not specify an interface, this command displays the local proxy ARP status for all interfaces.

Usage guidelines

You can use this command to check whether local proxy ARP is enabled or disabled.

Examples

# Display the local proxy ARP status for HundredGigE 1/0/1.

<Sysname> display local-proxy-arp interface hundredgige 1/0/1

Interface HundredGigE1/0/1

Local Proxy ARP status: enabled

Related commands

local-proxy-arp enable

display proxy-arp

Use display proxy-arp to display the proxy ARP status.

Syntax

display proxy-arp [ interface interface-type interface-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

interface interface-type interface-number: Specifies an interface by its type and number. If you do not specify an interface, this command displays the proxy ARP status for all interfaces.

Usage guidelines

You can use this command to check whether proxy ARP is enabled or disabled.

Examples

# Display the proxy ARP status on HundredGigE 1/0/1.

<Sysname> display proxy-arp interface hundredgige 1/0/1

Interface HundredGigE1/0/1

Proxy ARP status: disabled

Related commands

proxy-arp enable

display proxy-arp statistics

Use display proxy-arp statistics to display statistics for proxy ARP reply packets.

Syntax

display proxy-arp statistics

Views

Any view

Predefined user roles

network-admin

network-operator

Usage guidelines

Use this command to view the historical statistics for proxy ARP reply packets.

This command provides the proxy ARP reply statistics for the most recent hour. It displays 1-second proxy ARP reply statistics for the most recent minute and displays 5-second statistics for the earlier period.

Examples

# Display proxy ARP reply statistics.

<Sysname> display proxy-arp statistics

Last 1 sec proxy count: 200

Last 2 sec proxy count: 400

…

Last 1 min proxy count: 12000

Last 5 min proxy count: 18000

Last 10 min proxy count: 24000

…

Last 60 min proxy count: 182445

Table 5 Command output

Field	Description
Last n sec proxy count:	Number of proxy ARP reply packets for the most recent nth second.
Last n min proxy count:	Number of proxy ARP reply packets for the most recent nth minute.

local-proxy-arp enable

Use local-proxy-arp enable to enable local proxy ARP.

Use undo local-proxy-arp enable to disable local proxy ARP.

Syntax

local-proxy-arp enable [ ip-range start-ip-address to end-ip-address ]

undo local-proxy-arp enable

Default

Local proxy ARP is disabled.

Views

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VXLAN VSI interface view

VLAN interface view

Predefined user roles

network-admin

Parameters

ip-range start-ip-address to end-ip-address: Specifies the IP address range for which local proxy ARP is enabled. The start IP address must be lower than or equal to the end IP address.

Usage guidelines

Proxy ARP enables a device on a network to answer ARP requests for an IP address not on that network. With proxy ARP, hosts in different broadcast domains can communicate with each other as they do on the same network.

Proxy ARP includes common proxy ARP and local proxy ARP.

Common proxy ARP allows communication between hosts that connect to different Layer 3 interfaces and reside in different broadcast domains.

Local proxy ARP allows communication between hosts that connect to the same Layer 3 interface and reside in different broadcast domains.

If you execute this command multiple times, the most recent configuration takes effect.

Examples

# Enable local proxy ARP on HundredGigE 1/0/1.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] local-proxy-arp enable

# Enable local proxy ARP on HundredGigE 1/0/1 for an IP address range.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] local-proxy-arp enable ip-range 1.1.1.1 to 1.1.1.20

Related commands

display local-proxy-arp

proxy-arp enable

Use proxy-arp enable to enable proxy ARP.

Use undo proxy-arp enable to disable proxy ARP.

Syntax

proxy-arp enable

undo proxy-arp enable

Default

Proxy ARP is disabled.

Views

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VXLAN VSI interface view

VLAN interface view

Predefined user roles

network-admin

Usage guidelines

Proxy ARP includes common proxy ARP and local proxy ARP.

Common proxy ARP allows communication between hosts that connect to different Layer 3 interfaces and reside in different broadcast domains.

Local proxy ARP allows communication between hosts that connect to the same Layer 3 interface and reside in different broadcast domains.

Examples

# Enable proxy ARP on HundredGigE 1/0/1.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] proxy-arp enable

Related commands

display proxy-arp

ARP snooping commands

arp snooping enable

Use arp snooping enable to enable ARP snooping.

Use undo arp snooping enable to disable ARP snooping.

Syntax

arp snooping enable

undo arp snooping enable

Default

ARP snooping is disabled.

Views

VLAN view

VSI view

Predefined user roles

network-admin

Examples

# Enable ARP snooping for VLAN 2.

<Sysname> system-view

[Sysname] vlan 2

[Sysname-vlan2] arp snooping enable

# Enable ARP snooping for VSI vsi1.

<Sysname> system-view

[Sysname] vsi vsi1

[Sysname-vsi-vsi1] arp snooping enable

display arp snooping

Use display arp snooping to display ARP snooping entries.

Syntax

display arp snooping { vlan [ vlan-id ] | vsi [vsi-name ] } [ slot slot-number ] [ count ]

display arp snooping vlan ip ip-address [ slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

vlan vlan-id: Displays ARP snooping entries for a VLAN. The vlan-id argument is in the range of 1 to 4094. If you do not specify a VLAN, this command deletes ARP snooping entries for all VLANs.

vsi vsi-name: Displays ARP snooping entries for a VSI. The vsi-name argument specifies a VSI name, a case-sensitive string of 1 to 31 characters. If you do not specify a VSI, this command displays ARP snooping entries for all VSIs.

ip ip-address: Displays the ARP snooping entry for the specified IP address.

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command displays ARP snooping entries for the active MPU.

Examples

# Display ARP snooping entries for VLAN 2.

<Sysname> display arp snooping vlan 2

IP Address MAC Address VLAN ID Interface Aging Status

3.3.3.3 0003-0003-0003 2 HGE1/0/1 20 Valid

3.3.3.4 0004-0004-0004 2 HGE1/0/2 5 Invalid

# Display ARP snooping entries for all VSIs.

<Sysname> display arp snooping vsi

IP address MAC address VSI name Link ID Aging(min)

1.1.1.2 000f-e201-0101 vsi1 0x70000 14

1.1.1.3 000f-e201-0202 vsi1 0x80000 18

1.1.1.4 000f-e201-0203 vsi2 0x90000 10

# Display the ARP snooping entry for IP address 1.1.1.1 in a VLAN.

<Sysname> display arp snooping vlan ip 1.1.1.1

IP address MAC address VLAN ID Interface Aging Status

1.1.1.1 001f-e201-0111 2 HGE1/0/1 15 Valid

# Display the number of the ARP snooping entries in all VSIs.

<Sysname> display arp snooping vsi count

Total entries: 3

Table 6 Command output

Field	Description
IP Address	IP address in an ARP snooping entry.
MAC Address	MAC address in the ARP snooping entry.
VLAN ID	ID of the VLAN to which the ARP snooping entry belongs.
Interface	Input interface in the ARP snooping entry.
Aging	Aging time for the ARP snooping entry in minutes. If the card learns an ARP snooping entry from another card, the card cannot learn the aging time of the entry, and this field displays N/A.
Status	Status of the ARP snooping entry: Valid, Invalid, Collision.
VSI name	Name of the VSI to which the ARP snooping entry belongs.
Link ID	Link ID in the ARP snooping entry. It uniquely identifies an AC or a VXLAN tunnel in the VSI.
Total entries	Number of ARP snooping entries.

Related commands

reset arp snooping

Use reset arp snooping to delete ARP snooping entries.

Syntax

reset arp snooping { vlan [ vlan-id ] | vsi [ vsi-name ] }

reset arp snooping vlan ip ip-address

Views

User view

Predefined user roles

network-admin

Parameters

vlan vlan-id: Deletes ARP snooping entries for the specified VLAN. The value range for the vlan-id argument is 1 to 4094. If you do not specify a VLAN, this command deletes ARP snooping entries for all VLANs.

vsi vsi-name: Deletes ARP snooping entries for the specified VSI. The vsi-name argument specifies a VSI name, a case-sensitive string of 1 to 31 characters. If you do not specify a VSI, this command deletes ARP snooping entries for all VSIs.

ip ip-address: Deletes the ARP snooping entry for the specified IP address.

Usage guidelines

If you do not specify any option, the command deletes all ARP snooping entries.

Examples

# Delete ARP snooping entries for VLAN 2.

<Sysname> reset arp snooping vlan 2

Related commands

display arp snooping

ARP fast-reply commands

arp fast-reply enable

Use arp fast-reply enable to enable ARP fast-reply for a VLAN.

Use undo arp fast-reply enable to disable ARP fast-reply for a VLAN.

Syntax

arp fast-reply enable

undo arp fast-reply enable

Default

ARP fast-reply is disabled on a VLAN.

Views

VLAN view

Predefined user roles

network-admin

Examples

# Enable ARP fast-reply for VLAN 2.

<Sysname> system-view

[Sysname] vlan 2

[Sysname-vlan2] arp fast-reply enable

ARP direct route advertisement commands

arp route-direct advertise

Use arp route-direct advertise to enable ARP direct route advertisement.

Use undo arp route-direct advertise to disable ARP direct route advertisement.

Syntax

arp route-direct advertise [ preference preference-value | tag tag-value ] *

undo arp route-direct advertise

Default

ARP direct route advertisement is disabled.

Views

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VLAN interface view

VSI interface view

Predefined user roles

network-admin

Parameters

preference preference-value: Specifies the preference for the ARP-advertised direct routes. The value range for the preference-value argument is 1 to 255, and the default is 0. The smaller the value, the higher the preference.

tag tag-value: Specifies the route tag for the ARP-advertised direct routes. The value range for the tag-value argument is 1 to 4294967295, and the default is 0.

Usage guidelines

If ARP direct route advertisement is configured, ARP advertises ARP entries to the route management module to generate direct routes with an optional preference or route tag. The route preference value determines the match order of a route. Dynamic routing protocols use the tag value as the route identifier when they redistribute the route.

If you execute this command multiple times, the most recent configuration takes effect.

Examples

# Enable ARP direct route advertisement on Layer 3 Ethernet interface HundredGigE 1/0/1.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] arp route-direct advertise

# Enable ARP direct route advertisement on Layer 3 Ethernet interface HundredGigE 1/0/1 and set the preference value to 1 for direct routes.

<Sysname> system-view

[Sysname] interface hundredgige 1/0/1

[Sysname-HundredGigE1/0/1] arp route-direct advertise preference 1

arp route-direct advertise delay

Use arp route-direct advertise delay to set a delay for generating direct routes based on ARP entries.

Use undo arp route-direct advertise delay to restore the default.

Syntax

arp route-direct advertise delay delay-time

undo arp route-direct advertise delay

Default

The device generates a direct route immediately after an ARP entry is learned on an interface enabled with ARP direct route advertisement.

Views

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Layer 3 aggregate interface view

Layer 3 aggregate subinterface view

VLAN interface view

VSI interface view

Predefined user roles

network-admin

Parameters

delay-time: Specifies the delay for ARP-based generation of direct routes. The value range is 0 to 3600 seconds.

Usage guidelines

Application scenarios

After you enable ARP direct route advertisement on an interface by using the arp route-direct advertise command, the device generates direct routes and adjacency table entries based on ARP entries learned on that interface. If the direct routes are generated before the adjacency table entries for them, temporary packet loss will occur due to lack of Layer 2 information for packet encapsulation. To avoid such an issue, use this command to set a route generation delay for ARP direct route advertisement on the interface.

Operating mechanism

After you enable ARP direct route advertisement and set a route generation delay for it on an interface, a delay timer starts when an ARP entry is learned on that interface.

If the configuration for ARP direct route advertisement is modified before the delay time expires, the device advertises the direct route based on the new settings when the timer expires.

If you change the delay setting after a delay timer starts for an ARP entry, the new setting takes effect. However, the timer does not reset.

· If the timer count is equal to or higher than the new delay setting, the device generates a direct route based on the ARP entry.

· If the timer count is lower than the new delay setting, the device generates a direct route based on the ARP entry when the amount of new delay time is reached.

Restrictions and guidelines

You can enable ARP direct route advertisement and set a delay for ARP-based generation of direct routes in any order. If you set the delay first and then enable ARP direct route advertisement, the device generates a direct route based on the ARP entry when the delay time is reached.

Examples

# Set a route generation delay for ARP direct route advertisement on Layer 3 Ethernet interface HundredGigE 1/0/1.

<Sysname> system-view

[Sysname] interface HundredGigE1/0/1

[Sysname-HundredGigE1/0/1] arp route-direct advertise delay 200

Related commands

arp route-direct advertise

display arp route-direct advertise

Use display arp route-direct advertise to display information about ARP direct route advertisement.

Syntax

display arp route-direct advertise interface interface-type interface-number

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

interface interface-type interface-number: Specifies an interface by its type and number. Make sure ARP direct route advertisement is enabled on the interface.

Usage guidelines

When ARP direct route advertisement is enabled, the device generates direct routes based on ARP entries for packet forwarding and route advertisement. You can use this command to verify that the route management module has generated direct routes for ARP entries as configured.

Examples

# Display the direct routes generated based on ARP entries on Hundredgige 1/0/1.

<Sysname> display arp route-direct advertise interface hundredgige 1/0/1

IP address MAC address VLAN/VSI Interface Route

1.1.1.1 02e0-f102-0023 1 HGE1/0/1 Yes

1.1.1.2 00e0-fc00-0001 12 HGE1/0/1 No

Table 7 Command output

Field	Description
IP address	IP address in the ARP entry.
MAC address	MAC address in the ARP entry.
VLAN/VSI	ID of the VLAN or index of the VSI to which the ARP entry belongs. This field displays two hyphens (--) in either of the following situations: · The ARP entry is an unresolved short static ARP entry. · The output interface of the ARP entry does not belong to the VLAN or VSI.
Interface	Output interface in the ARP entry.
Route	Whether or not a direct route has been generated based on the ARP entry: · Yes—A direct route has been generated based on the ARP entry. · No—No direct route has been generated based on the ARP entry.

Related commands

arp route-direct advertise

06-Layer 3—IP Services Command Reference

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arp static

arp timer aging

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display arp ip-address

display arp vpn-instance

reset arp

gratuitous-arp-learning enable

display local-proxy-arp

display proxy-arp

local-proxy-arp enable

ARP snooping commands

display arp snooping

reset arp snooping

ARP fast-reply commands

ARP direct route advertisement commands

arp route-direct advertise delay

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