H3C S7500E Series Ethernet Switches Operation Manual

Operation Manual – ARP
H3C S7500E Series Ethernet Switches Chapter 1 ARP Configuration
1-4
1) A dynamic entry is automatically created and maintained by ARP. It can get aged,
be updated by a new ARP packet, or be overwritten by a static ARP entry. When
the aging timer expires or the port goes down, the corresponding dynamic ARP
entry will be removed.
2) A static ARP entry is manually configured and maintained. It cannot get aged or be
overwritten by a dynamic ARP entry. It can be permanent or non-permanent.
z A permanent static ARP entry can be directly used to forward packets. When
configuring a permanent static ARP entry, you must configure a VLAN and
outbound port for the entry besides the IP address and MAC address.
z A non-permanent static ARP entry cannot be directly used for forwarding data.
When configuring a non-permanent static ARP entry, you only need to configure
the IP address and MAC address. When forwarding IP packets, the device sends
an ARP request. If the source IP and MAC addresses in the received ARP reply
are the same as the configured IP and MAC addresses, the device adds the port
receiving the ARP reply into the static ARP entry. Now the entry can be used for
forwarding IP packets.
 Note:
Usually ARP dynamically implements and automatically seeks mappings from IP
addresses to MAC addresses, without manual intervention.
1.2 Configuring ARP
1.2.1 Configuring a Static ARP Entry
A static ARP entry is effective when the device works normally. However, when a VLAN
or VLAN interface to which a static ARP entry corresponds is deleted, the entry, if
permanent, will be deleted, and if non-permanent and resolved, will become
unresolved.
Follow these steps to configure a static ARP entry:
To do… Use the command… Remarks
Enter system view
system-view
—
Configure a permanent
static ARP entry
arp static ip-address
mac-address vlan-id
interface-type
interface-number
Required
No permanent static ARP
entry is configured by
default.