3Com 2928 - Baseline Plus Switch PWR, User Manual

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1-3
Static ARP entry
A static ARP entry is manually configured and maintained. It cannot get aged or be overwritten by a
dynamic ARP entry.
Using static ARP entries enhances communication security. After a static ARP entry is specified, only a
specific MAC address is associated with the specified IP address. Attack packets cannot modify the
IP-to-MAC mapping. Thus, communications between devices are protected.
Static ARP entries can be classified into 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 an outbound interface for the entry
besides the IP address and the MAC address.
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A non-permanent static ARP entry has only an IP address and a MAC address configured. It
cannot be directly used for forwarding data. If a non-permanent static ARP entry matches an IP
packet to be forwarded, the device sends an ARP request first. If the sender IP and MAC
addresses in the received ARP reply are the same as those in the non-permanent static ARP entry,
the device adds the interface receiving the ARP reply to the non-permanent static ARP entry. Then
the entry can be used for forwarding IP packets.
Usually ARP dynamically resolves IP addresses to MAC addresses, without manual intervention.
Managing ARP Entries
Displaying ARP Entries
Select
Network
>
ARP Management
from the navigation tree to enter the default
ARP Table
page
shown in Figure 1-3 . All ARP entries are displayed on the page.
Figure 1-3 ARP Table
configuration page