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Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter32 Understanding and Configuring Dynamic ARP Inspection
Configuring Dynamic ARP Inspection
Gi3/41 Untrusted 15 1
Gi3/42 Untrusted 15 1
Gi3/43 Untrusted 15 1
Gi3/44 Untrusted 15 1
Gi3/45 Untrusted 15 1
Gi3/46 Trusted None N/A
Gi3/47 Untrusted 15 1
Gi3/48 Untrusted 15 1
SwitchB# show errdisable recovery
ErrDisable Reason Timer Status
----------------- --------------
udld Disabled
bpduguard Disabled
security-violatio Disabled
channel-misconfig Disabled
vmps Disabled
pagp-flap Disabled
dtp-flap Disabled
link-flap Disabled
l2ptguard Disabled
psecure-violation Disabled
gbic-invalid Disabled
dhcp-rate-limit Disabled
unicast-flood Disabled
storm-control Disabled
arp-inspection Enabled
Timer interval: 300 seconds
Interfaces that will be enabled at the next timeout:
SwitchB#
1w2d: %SW_DAI-4-PACKET_RATE_EXCEEDED: 101 packets received in 739 milliseconds on Gi3/31.
1w2d: %PM-4-ERR_DISABLE: arp-inspection error detected on Gi3/31, putting Gi3/31 in
err-disable state
SwitchB# show clock
*02:21:43.556 UTC Fri Feb 4 2005
SwitchB#
SwitchB# show interface g3/31 status
Port Name Status Vlan Duplex Speed Type
Gi3/31 err-disabled 100 auto auto 10/100/1000-TX
SwitchB#
SwitchB#
1w2d: %PM-4-ERR_RECOVER: Attempting to recover from arp-inspection err-disable state on
Gi3/31
SwitchB# show interface g3/31 status
Port Name Status Vlan Duplex Speed Type
Gi3/31 connected 100 a-full a-100 10/100/1000-TX
SwitchB# show clock
*02:27:40.336 UTC Fri Feb 4 2005
SwitchB#
Performing Validation Checks

Dynamic ARP inspection intercepts, logs, and discards ARP packets with invalid IP-to-MAC address

bindings. You can configure the switch to perform additional checks on the destination MAC address,

the sender and target IP addresses, and the source MAC address.