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arp inspection
To view entries in the ARP database, use the show arp inspection database command.
DellEMC#show arp inspection database
Protocol Address Age(min) Hardware Address Interface VLAN CPU
---------------------------------------------------------------------
Internet 10.1.1.251 - 00:00:4d:57:f2:50 Te 1/2 Vl 10 CP
Internet 10.1.1.252 - 00:00:4d:57:e6:f6 Te 1/1 Vl 10 CP
Internet 10.1.1.253 - 00:00:4d:57:f8:e8 Te 1/3 Vl 10 CP
Internet 10.1.1.254 - 00:00:4d:69:e8:f2 Te 1/5 Vl 10 CP
DellEMC#
To see how many valid and invalid ARP packets have been processed, use the show arp inspection statistics
command.
DellEMC#show arp inspection statistics
Dynamic ARP Inspection (DAI) Statistics
---------------------------------------
Valid ARP Requests : 0
Valid ARP Replies : 1000
Invalid ARP Requests : 1000
Invalid ARP Replies : 0
DellEMC#
Configuring dynamic ARP inspection-limit
To configure dynamic ARP inspection rate limit on a port, perform the following task.
1. Enter into global configuration mode.
EXEC Privilege mode
configure terminal
2. Select the interface to be configured.
CONFIGURATION mode
interface interface-name
3. Configure ARP packet inspection rate limiting.
INTERFACE CONFIGURATION mode
arp inspection-limit {rate pps [interval seconds]}
The rate packet per second (pps) range is from 1 to 2048. The default is 15.
The rate burst interval range is from 1 to 15 seconds. The default is 1.
DellEMC# show running-config interface tengigabitethernet 1/10
interface TenGigabitEthernet 1/10
no ip address
switchport
arp inspection-limit rate 15 interval 1
no shutdown
DellEMC#
Bypassing the ARP Inspection
You can configure a port to skip ARP inspection by defining the interface as trusted, which is useful in multi-switch
environments.
ARPs received on trusted ports bypass validation against the binding table. All ports are untrusted by default.
To bypass the ARP inspection, use the following command.
Specify an interface as trusted so that ARPs are not validated against the binding table.
INTERFACE mode
Dynamic Host Configuration Protocol (DHCP)
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