ARP

Context

On a local area network (LAN), a host or network device must learn the IP address of the destination host or device before sending data to it. Additionally, the host or network device must learn the physical address (MAC address) of the destination host or device because IP packets must be encapsulated into frames for transmission over a physical network. Therefore, the mapping from an IP address into a physical address is required. Address Resolution Protocol (ARP) is introduced to map IP addresses to physical addresses (Ethernet MAC addresses).

Procedure

Create a static ARP entry.

Choose Configuration > Advanced Services > IP Services > ARP > Static ARP to access the Static ARP page.

Click Create.

Table 1 describes parameters on the page.

**Table 1** Creating a static ARP entry
Parameter	Description
Destination IP address	Enters the destination IP address, for example, 10.10.10.1. NOTE: This parameter cannot be set to the virtual IP address of a VRRP group configured on a VLANIF interface. Otherwise, an incorrect host route will be generated, causing forwarding errors.
Destination MAC address	Enters the Ethernet MAC address mapping the IP address, for example 00e0-fc12-3456.
VLAN ID	Enters the VLAN ID corresponding to the IP address. NOTE: If you enter a VLAN ID, the created ARP entry is in the specified VLAN. The VLANIF interface of the VLAN must be on the same network segment as the destination IP address.
Outbound interface	Click to select the outbound interface of ARP packets, for example, GigabitEthernet0/0/1. NOTE: The interface must be a member of the specified VLAN.

Set the parameters.

The destination IP address and the IP address of the outbound interface must be on the same network segment.
Click OK.

Modify a static ARP entry.
1. Choose Configuration > Advanced Services > IP Services > ARP > Static ARP to access the Static ARP page.
2. Click a destination IP address in the static ARP entry list to access the corresponding static ARP entry modification page.
  Table 1 describes parameters on the page.
  
  The destination IP address cannot be modified.
3. Modify the configuration parameters.
4. Click OK.
Delete a static ARP entry.
1. Choose Configuration > Advanced Services > IP Services > ARP > Static ARP to access the Static ARP page.
2. Select a record that you want to delete and click Delete. The system asks you whether to delete the record.
3. Click OK.
Clear all static ARP entries.
1. Choose Configuration > Advanced Services > IP Services > ARP > Static ARP to access the Static ARP page.
2. Click Clear ALL Static ARP Entries. The system asks you whether to delete all static ARP entries.
3. Click OK.
Update a static ARP entry.
1. Choose Configuration > Advanced Services > IP Services > ARP > Static ARP to access the Static ARP page.
2. Click Refresh.
Delete a dynamic ARP entry.
1. Choose Configuration > Advanced Services > IP Services > ARP > Dynamic ARP to access the Dynamic ARP page.
2. Select a record that you want to delete and click Delete. The system asks you whether to delete the record.
3. Click OK.
Clear all dynamic ARP entries.
1. Choose Configuration > Advanced Services > IP Services > ARP > Dynamic ARP to access the Dynamic ARP page.
2. Click Clear ALL Dynamic ARP Entries. The system asks you whether to delete all dynamic ARP entries.
3. Click OK.
Update a dynamic ARP entry.
1. Choose Configuration > Advanced Services > IP Services > ARP > Dynamic ARP to access the Dynamic ARP page.
2. Click Refresh.
Configure fixed ARP.
1. Choose Configuration > Advanced Services > IP Services > ARP > Dynamic ARP to access the Dynamic ARP page.
2. Select the dynamic ARP entries to be fixed and click Fix MAC.
  If the configuration succeeds, you can query the fixed ARP entries on the Static ARP page. If the configuration fails, an error message is displayed.
  - Successful executions: indicates the number of dynamic ARP entries that are fixed successfully.
  - Failed executions: indicates the number of dynamic ARP entries that fail to be fixed.