1# arp 2 3 4## Command Function 5 6Hosts on an Ethernet communicate with each other using MAC addresses. IP addresses must be converted into MAC addresses to enable communication between hosts on a LAN (Ethernet). To achieve this purpose, the host stores a table containing the mapping between IP addresses and MAC addresses. This table is called an Address Resolution Protocol (ARP) cache table. Before sending an IP packet to a LAN, the host looks up the destination MAC address in the ARP cache table. The ARP cache table is maintained by the TCP/IP stack. You can run the **arp** command to view and modify the ARP cache table. 7 8 9## Syntax 10 11arp 12 13arp [_-i IF_] -s *IPADDR HWADDR* 14 15arp [_-i IF_] -d *IPADDR* 16 17 18## Parameters 19 20**Table 1** Parameter description 21 22| Parameter| Description| Value Range| 23| -------- | -------- | -------- | 24| No parameter| Prints the content of the ARP cache table.| N/A | 25| -i IF | Specifies the network port. This parameter is optional.| N/A | 26| -s IPADDR<br>HWADDR | Adds an ARP entry. The second parameter is the IP address and MAC address of the other host on the LAN.| N/A | 27| -d IPADDR | Deletes an ARP entry.| N/A | 28 29 30## Usage Guidelines 31 32- The **arp** command is used to query and modify the ARP cache table of the TCP/IP stack. If ARP entries for IP addresses on different subnets are added, the protocol stack returns a failure message. 33 34- This command can be used only after the TCP/IP protocol stack is enabled. 35 36 37## Example 38 39Run **arp**. 40 41ARP cache table information: 42 43``` 44OHOS # arp 45Address HWaddress Iface Type 46192.168.1.10 E6:2B:99:2C:4B:20 eth0 static 47``` 48 49**Table 2** Parameter description 50 51| Parameter| Description| 52| -------- | -------- | 53| Address | IPv4 address of the network device.| 54| HWaddress | MAC address of the network device.| 55| Iface | Name of the port used by the ARP entry.| 56| Type | Whether the ARP entry is dynamic or static. A dynamic ARP entry is automatically created by the protocol stack, and a static ARP entry is added by the user. | 57