User Manual

24-Port and 48-Port Gigabit Ethernet PoE+ Smart Switches with 4 SFP Ports
Configure System Information User Manual137
7. Select whether to display physical interfaces, LAGs, or both by clicking one of the following
links above the table heading:
•1 (the unit ID of the switch). Only physical interfaces are displayed. This is the default
setting.
•
LAG. Only LAGs are displayed.
• All. Both physical interfaces and LAGs are displayed.
8. Click the Clear button to clear all interfaces statistics.
The following table describes the DHCP snooping statistics.
Table 27. DHCP Snooping Statistics information
Field Description
Interface The interface associated with the rest of the data in the row.
MAC Verify Failures The number of DHCP messages that were dropped because the source MAC address
and client hardware address did not match. MAC address verification is performed only if
it is globally enabled.
Client Ifc Mismatch The number of packets that were dropped by DHCP snooping because the interface and
VLAN on which the packet was received do not match the client’
s interface and VLAN
information stored in the binding database.
DHCP Server Msgs
Received
The number of DHCP server messages ((DHCPOFFER, DHCP
ACK, DHCPNAK,
DHCPRELEASEQUER
Y) that were dropped on an untrusted port.
Configure Dynamic ARP Inspection
Dynamic ARP Inspection (DAI) is a security feature that rejects invalid and malicious ARP
packets. DAI prevents a class of man-in-the-middle attacks where an unfriendly station
intercepts traffic for other stations by poisoning the ARP caches of its unsuspecting
neighbors. The malicious attacker sends ARP requests or responses mapping another
station’s IP address to its own MAC address.
When DAI is enabled, the switch drops ARP packets whose sender MAC address and
sender IP address do not match an entry in the DHCP snooping bindings database.
Y
ou can
optionally configure additional ARP packet validation.