Dell PowerConnect 8024 User Manual

Managing a Switch Stack 173
NSF and DHCP Snooping
Figure 9-14 illustrates an L2 access switch running DHCP snooping. DHCP
snooping only accepts DHCP server messages on ports configured as
trusted
ports. DHCP snooping listens to DHCP messages to build a bindings
database that lists the IP address the DHCP server has assigned to each host.
IP Source Guard (IPSG) uses the bindings database to filter data traffic in
hardware based on source IP address and source MAC address. Dynamic ARP
Inspection (DAI) uses the bindings database to verify that ARP messages
contain a valid sender IP address and sender MAC address. DHCP snooping
checkpoints its bindings database.
Figure 9-14. NSF and DHCP Snooping
If the stack master fails, all hosts connected to that unit lose network access
until that unit reboots. The hardware on surviving units continues to enforce
source filters IPSG installed prior to the failover. Valid hosts continue to
communicate normally. During the failover, the hardware continues to drop
data packets from unauthorized hosts so that security is not compromised.

Dell PowerConnect 8024 Specifications

General

Switching Capacity	480 Gbps
Stackable	Yes
Device Type	Switch
Enclosure Type	Rack-mountable
Power Redundancy	Optional
Width	17.3 in
Height	1.7 in
Jumbo Frame Support	Yes
Ports	24 x 10 Gigabit SFP+
Management	Web-based GUI, Command Line Interface (CLI), SNMP
VLAN Support	Yes
Power Supply	Internal
Routing Protocol	Static routing
Features	Quality of Service (QoS), VLAN support
Compliant Standards	IEEE 802.3, IEEE 802.3u, IEEE 802.3ab, IEEE 802.3z
Operating Temperature	0 to 45 °C
Storage Temperature	-20 to 70 °C
Relative Humidity	10% to 90% (non-condensing)
MAC Address Table Size	32, 000 entries