Concept Guide

• Enabling Proxy ARP (optional)
• Clearing ARP Cache (optional)
• ARP Learning via Gratuitous ARP
• ARP Learning via ARP Request
• Conguring ARP Retries
Conguring Static ARP Entries
ARP dynamically maps the MAC and IP addresses, and while most network host support dynamic mapping, you can congure an ARP
entry (called a static ARP) for the ARP cache.
To congure a static ARP entry, use the following command.
• Congure an IP address and MAC address mapping for an interface.
CONFIGURATION mode
arp ip-address mac-address interface
– ip-address: IP address in dotted decimal format (A.B.C.D).
– mac-address: MAC address in nnnn.nnnn.nnnn format.
– interface: enter the interface type.
◦ For the Management interface, enter the keyword ManagementEthernet then the slot/port information. The slot range is
from 0 to 1 and the port range is 0.
◦ For a Port Channel interface, enter the keywords portchannel then a number. The range is from 1 to 128.
◦ For a 10-Gigabit Ethernet interface, enter the keyword TenGigabitEthernet then the slot/port information.
◦ For a 40-Gigabit Ethernet interface, enter the keyword fortyGigE then the slot/port information.
◦ For a port extender (PE) Gigabit Ethernet interface, enter the keyword peGigE then the pe-id/stack-unit /port-id information.
The
pe-id is a port-extender ID number from 0 to 255; the stack-unit unit-number is from 0 to 7; and the port-id range is from 1
to 48.
◦ For a port extender 10-Gigabit Ethernet interface, enter the keyword peTenGigE then the pe-id / stack-unit / port-id
information. The pe-id range is from 0 to 255; the stack-unit unit-number range is from 0 to 7; and the port-id range is 25 to 28
or 49 to 52 depending on the PE.
Example of the show arp Command
These entries do not age and can only be removed manually. To remove a static ARP entry, use the no arp ip-address command.
To view the static entries in the ARP cache, use the show arp static command in EXEC privilege mode.
Dell#show arp
Protocol Address Age(min) Hardware Address Interface VLAN CPU
--------------------------------------------------------------------------------
Internet 10.1.2.4 17 08:00:20:b7:bd:32 Ma 1/0 - CP
Dell#
Conguring ARP Inspection Trust
Use the arp-inspection-trust command to specify a port or an interface as trusted so that ARP frames are not validated against
the binding table. By default, this feature is disabled.
• Enable ARP learning via gratuitous ARP.
INTERFACE Mode
IPv4 Routing
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