Web Management Guide-R05

Table Of Contents
Chapter 12
| Security Measures
ARP Inspection
– 332
Time-Range
– Name of a time range.
Hit
– Shows the number of packets matching this ACL.
7
Clear Counter
– Clears the hit counter for the 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 209: 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 Global Configuration” on page 366). This database
is built by DHCP snooping if it is enabled on globally on the switch and on the
7. Due to a hardware limitation, statistics are only displayed for permit rules.