switchB(config)#
Step 3
Configure Ethernet interface 1/4 as trusted.
switchB(config)#
interface ethernet 1/4
switchB(config-if)#
ip arp inspection trust
switchB(config-if)#
exit
switchB(config)#
exit
switchB#
show ip arp inspection interface ethernet 1/4
Interface
Trust State
Rate (pps)
Burst Interval
-------------
-----------
----------
--------------
Ethernet1/4
Trusted
15
5
switchB#
Step 4
Verify the list of DHCP snooping bindings.
switchB#
show ip dhcp snooping binding
MacAddress
IpAddress
LeaseSec
Type
VLAN
Interface
-----------------
---------------
--------
-------------
----
-------------
00:01:00:01:00:01
10.0.0.2
4995
dhcp-snooping
1
Ethernet1/4
switchB#
Step 5
Check the statistics before and after DAI processes any packets.
switchB#
show ip arp inspection statistics vlan 1
Vlan : 1
-----------
ARP Req Forwarded
= 0
ARP Res Forwarded
= 0
ARP Req Dropped
= 0
ARP Res Dropped
= 0
DHCP Drops
= 0
DHCP Permits
= 0
SMAC Fails-ARP Req = 0
SMAC Fails-ARP Res = 0
DMAC Fails-ARP Res = 0
IP Fails-ARP Req
= 0
IP Fails-ARP Res
= 0
switchB#
If Host 2 sends out an ARP request with the IP address 10.0.0.2 and the MAC address 0001.0001.0001, the packet is
forwarded, and the statistics are updated.
switchB#
show ip arp inspection statistics vlan 1
Vlan : 1
-----------
ARP Req Forwarded
= 1
ARP Res Forwarded
= 0
ARP Req Dropped
= 0
ARP Res Dropped
= 0
DHCP Drops
= 0
DHCP Permits
= 1
SMAC Fails-ARP Req = 0
SMAC Fails-ARP Res = 0
DMAC Fails-ARP Res = 0
IP Fails-ARP Req
= 0
IP Fails-ARP Res
= 0
switchB#
Cisco Nexus 9000 Series NX-OS Security Configuration Guide, Release 9.x
403
Configuring Dynamic ARP Inspection
Configuring Device B