Chapter 9
| General Security Measures
ARP Inspection
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◆ When ARP Inspection is disabled, all ARP request and reply packets bypass the
ARP Inspection engine and their manner of switching matches that of all other
packets.
◆ Disabling and then re-enabling global ARP Inspection will not affect the ARP
Inspection configuration for any VLANs.
◆ When ARP Inspection is disabled globally, it is still possible to configure ARP
Inspection for individual VLANs. These configuration changes will only become
active after ARP Inspection is globally enabled again.
Example
Console(config)#ip arp inspection
Console(config)#
ip arp inspection filter This command specifies an ARP ACL to apply to one or more VLANs. Use the no
form to remove an ACL binding. Use the no form to remove an ACL binding.
Syntax
ip arp inspection filter arp-acl-name vlan {vlan-id | vlan-range} [static]
no ip arp inspection filter arp-acl-name vlan {vlan-id | vlan-range}
arp-acl-name - Name of an ARP ACL. (Maximumlength:16characters)
vlan-id - VLAN ID. (Range: 1-4094)
vlan-range - A consecutive range of VLANs indicated by the use a hyphen,
or a random group of VLANs with each entry separated by a comma.
static - ARP packets are only validated against the specified ACL, address
bindings in the DHCP snooping database is not checked.
Default Setting
ARP ACLs are not bound to any VLAN
Static mode is not enabled
Command Mode
Global Configuration
Command Usage
◆ ARP ACL configuration commands are described under “ARP ACLs” on
page 378.
◆ If static mode is enabled, the switch compares ARP packets to the specified ARP
ACLs. Packets matching an IP-to-MAC address binding in a permit or deny rule
are processed accordingly. Packets not matching any of the ACL rules are
dropped. Address bindings in the DHCP snooping database are not checked.