ECS4660-28F_Management Guide-R03

C HAPTER 13 | Security Measures
ARP Inspection
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◆ Clear Counter – Clears hit counter for rules in specified ACL.
WEB INTERFACE
To show statistics for ACL hardware counters:
1. Click Security, ACL.
2. Select Configure Interface from the Step list.
3. Select Show Hardware Counters from the Action list.
4. Select a port.
5. Select ingress or egress traffic.
Figure 211: Showing ACL Statistics
ARP INSPECTION
ARP Inspection is a security feature that validates the MAC Address
bindings for Address Resolution Protocol packets. It provides protection
against ARP traffic with invalid MAC-to-IP address bindings, which forms
the basis for certain “man-in-the-middle” attacks. This is accomplished by
intercepting all ARP requests and responses and verifying each of these
packets before the local ARP cache is updated or the packet is forwarded to
the appropriate destination. Invalid ARP packets are dropped.
ARP Inspection determines the validity of an ARP packet based on valid
IP-to-MAC address bindings stored in a trusted database – the DHCP
snooping binding database (see "DHCP Snooping Configuration" on
page 446). This database is built by DHCP snooping if it is enabled on
globally on the switch and on the required VLANs. ARP Inspection can also
validate ARP packets against user-configured ARP access control lists
(ACLs) for hosts with statically configured addresses (see "Configuring an
ARP ACL" on page 406).
5. Due to a hardware limitation, statistics are only displayed for permit rules.