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 public IP address after NAT.

· 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 public IP address after NAT.

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-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

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

Usage guidelines

An IP unnumbered interface is an interface configured with the ip address unnumbered command. An IP unnumbered interface cannot learn the ARP entry of the peer device if the unnumbered interface and the peer device are on different subnets. To ensure communication between them, you can enable this feature on the IP unnumbered interface.

If an IP unnumbered interface is disabled from learning ARP entries for different subnets, existing ARP entries learned for different subnets are deleted after they age out.

This feature takes effect only on IP unnumbered interfaces. Do not enable this feature on a non-IP unnumbered interface. Otherwise, ARP entry learning on that interface might fail.

Examples

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

<Sysname> system-view

[Sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] ip address unnumbered interface gigabitethernet 0/0/2

[Sysname-GigabitEthernet0/0/1] 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 4096 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

EVB VSI interface/EVB VSI aggregate interface 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 4096.

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 GigabitEthernet 0/0/1 to learn a maximum of 10 dynamic ARP entries.

<Sysname> system-view

[Sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] 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

A device can learn a maximum of 4096 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 4096.

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 mode uni

Use arp mode uni to configure a port as a customer-side port.

Use undo arp mode to restore the default.

Syntax

arp mode uni

undo arp mode

Default

A port operates as a network-side port.

Views

VLAN interface view

VXLAN VSI interface view

Predefined user roles

network-admin

Usage guidelines

By default, the device associates an ARP entry with routing information when the device learns an ARP entry. The ARP entry provides the next hop information for routing. To save hardware resources, you can use this command to specify a port that connects to a user terminal as a customer-side port. The device will not associate the routing information with the learned ARP entries.

Examples

# Configure VLAN-interface 2 as a customer-side port.

<Sysname> system-view

[Sysname] interface vlan-interface 2

[Sysname-Vlan-interface2] arp mode uni

arp smooth

Use arp smooth to synchronize ARP entries from the active MPU to all other cards.

Syntax

arp smooth

Views

User view

Predefined user roles

network-admin

Examples

# Synchronize ARP entries from the active MPU to all other cards.

<Sysname> arp smooth

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 ] [ 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.

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 the description for the static ARP entry, a case-sensitive string of 1 to 255 characters. By default, a static ARP entry does not have a description.

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.

Examples

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

<Sysname> system-view

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

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

The aging timer for dynamic ARP entries is 20 minutes.

Views

System 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

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.

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

Related commands

display arp timer aging

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

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.

vlan vlan-id: Specifies a VLAN by its VLAN ID. The VLAN ID is in the range of 1 to 4094.

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.

count: Displays the number of ARP entries.

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 GE0/0/1 -- S

1.1.1.2 00e0-fc00-0001 12 GE0/0/2 960 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 : GE0/0/1 SVLAN/CVLAN : 1/--

VPN instance : --

Link ID : --

Service instance : --

VXLAN ID : --

VSI name : --

VSI interface : --

Description : --

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

Type : Dynamic Aging : 960 seconds

Interface : GE0/0/2 SVLAN/CVLAN : 12/--

VPN instance : --

Link ID : --

Service instance : --

VXLAN ID : --

VSI name : --

VSI interface : --

Description : --

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 : --

Description : --

# 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.
Description	Description for the static ARP entry.

‌

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: 2048

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 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: GigabitEthernet0/0/1

New interface: GigabitEthernet0/0/2

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: GigabitEthernet0/0/1

New interface: GigabitEthernet0/0/2

Old SVLAN/CVLAN: 100/--

New SVLAN/CVLAN: 100/--

Old MAC: 00e0-ca63-8141

New MAC: 00e0-ca63-8142

Table 2 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: GigabitEthernet0/0/1

SVLAN/CVLAN: 100/2

After:

interface: GigabitEthernet0/0/2

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: GigabitEthernet0/0/1

SVLAN/CVLAN: 100/--

After:

interface: GigabitEthernet0/0/2

SVLAN/CVLAN: 100/--

Table 3 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.

count: Displays the number of ARP entries.

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 GigabitEthernet 0/0/1 to send gratuitous ARP packets every 300 milliseconds.

<Sysname> system-view

[Sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] 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 GigabitEthernet 0/0/1.

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

Interface GigabitEthernet0/0/1

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 GigabitEthernet 0/0/1.

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

Interface GigabitEthernet0/0/1

Proxy ARP status: disabled

Related commands

proxy-arp enable

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 GigabitEthernet 0/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] local-proxy-arp enable

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

<Sysname> system-view

[Sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] 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 GigabitEthernet 0/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] proxy-arp enable

Related commands

display proxy-arp

ARP PnP commands

arp pnp

Use arp pnp to enable the ARP plug and play (PnP) feature.

Use undo arp pnp to disable the ARP PnP feature.

Syntax

arp pnp

undo arp pnp

Default

The ARP PnP feature is disabled.

Views

Layer 3 Ethernet interface view

Layer 3 Ethernet subinterface view

Predefined user roles

network-admin

Usage guidelines

CAUTION:

Features that use ARP entries, for example, static routes and proxy ARP, cannot operate correctly when the ARP PnP feature is enabled.

This command is typically configured on a gateway. The ARP PnP feature allows end users to access the gateway without changing their IP addresses on subnets different from the subnet where the gateway resides.

To make ARP PnP operate correctly on an interface, make sure the following requirements are met:

· The interface has a primary IP address.

· NAT is configured on the interface that connects to the external network.

· ARP entries on the interface are all deleted by using the reset arp command before you enable the ARP PnP feature.

The ARP PnP feature generates agent IP addresses based on the primary IP address and mask length of the interface. The maximum number of agent IP addresses allowed on an interface is the smaller value of the following items:

· The maximum number of host IP addresses allowed by the mask length. The interface's primary IP address is excluded. For example, if the mask length is 24, a maximum of 253 agent IP addresses can be generated.

· The maximum number of dynamic ARP entries that the interface can learn.

Examples

# Enable the ARP PnP feature.

<Sysname> system-view

[sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] arp pnp

display arp pnp

Use display arp pnp to display ARP PnP mappings.

Syntax

display arp pnp [ 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, the command displays ARP PnP mappings for all interfaces.

Examples

# Display all ARP PnP mappings.

<Sysname> display arp pnp

Total number of entries : 5

Agent IP address User IP address MAC address Interface Aging

1.1.1.2 20.1.1.1 00e0-fc00-0001 GE0/0/1 10

1.1.1.3 193.1.1.70 00e0-fe50-6503 GE0/0/1 5

2.2.2.2 192.168.0.115 000d-88f7-9f7d GE0/0/2 11

3.3.3.3 192.168.0.39 0012-a990-2241 GE0/0/3 5

3.3.3.4 22.1.1.1 000c-299d-c041 GE0/0/3 14

# Display ARP PnP mappings on GigabitEthernet 0/0/1.

<Sysname> display arp pnp interface gigabitethernet 0/0/1

Total number of entries : 2

Agent IP address User IP address MAC address Interface Aging

1.1.1.2 20.1.1.1 00e0-fc00-0001 GE0/0/1 10

1.1.1.3 193.1.1.70 00e0-fe50-6503 GE0/0/1 5

Table 4 Command output

Field	Description
Agent IP address	Agent IP address the ARP PnP feature generates for the user.
User IP address	IP address of the user.
MAC address	MAC address of the user.
Interface	Interface that connects to the user.
Aging	Aging time (in minutes) of the mapping.

‌

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

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

Predefined user roles

network-admin

Examples

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

<Sysname> system-view

[Sysname] interface gigabitethernet 0/0/1

[Sysname-GigabitEthernet0/0/1] arp route-direct advertise

07-Layer 3—IP Services Command Reference

arp smooth

arp timer aging

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 direct route advertisement commands

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